Towing Weight Calculator Caravan

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Caravan Towing Weight Calculator

Ensure Safe Towing for Your Caravan Adventures

Towing Weight Safety Check

The maximum weight your caravan is designed to carry. Found on the caravan's VIN plate.
The actual weight of your caravan when loaded for travel.
The maximum weight your car is designed to tow. Found in vehicle handbook/specs.
The maximum vertical weight allowed on the tow hitch. Found in vehicle handbook/specs.
The actual vertical weight your caravan exerts on the tow hitch.

Towing Safety Assessment

Towing Ratio

Nose Weight Ratio

Weight Difference

How it's Calculated:

The primary result indicates if your caravan's loaded weight is within the recommended limits relative to your tow vehicle's capacity. We check:

  • Towing Ratio: (Caravan Loaded Weight / Tow Vehicle MAM) * 100%. Recommended < 85%.
  • Nose Weight Ratio: (Caravan Actual Nose Weight / Caravan Loaded Weight) * 100%. Recommended 5-7%.
  • Nose Weight Limit: Caravan Actual Nose Weight vs. Tow Vehicle Max Nose Weight.
  • Weight Difference: Tow Vehicle MAM – Caravan Loaded Weight.

Safe towing requires all these factors to be within acceptable ranges.

Towing Weight Considerations

Key Towing Weight Factors
Factor Description Impact on Safety
Caravan's MAM The maximum weight the caravan manufacturer has certified it can be. Crucial for calculating towing ratio. Exceeding this means the caravan itself is overloaded.
Caravan's Loaded Weight The actual weight of the caravan plus all its contents. Directly impacts towing ratio and stability. Must be less than MAM.
Tow Vehicle's MAM (or GVM) The maximum weight the tow vehicle can carry and tow. This is often the limiting factor. Determines the absolute maximum your vehicle can safely tow.
Tow Vehicle's Max Towing Capacity The maximum weight the manufacturer states the vehicle can tow. The legal and mechanical limit. Often lower than MAM for lighter vehicles.
Tow Vehicle's Max Nose Weight The maximum downward force allowed on the tow ball by the vehicle manufacturer. Essential for stability; too little can cause snaking, too much can damage the hitch or vehicle.
Caravan's Actual Nose Weight The actual downward force exerted by the caravan hitch onto the tow ball. Must be within both the caravan's and tow vehicle's limits and generally 5-7% of loaded caravan weight for stability.
Axle Loads The weight distributed on each axle of the caravan and tow vehicle. Affects vehicle handling and can lead to tyre blowouts or suspension damage if exceeded.

Towing Stability Chart

This chart illustrates how nose weight affects the stability of your caravan setup.

Optimal Stability

Potential Instability (too low nose weight)

Potential Instability (too high nose weight)

Understanding Caravan Towing Weight

{primary_keyword} is a critical concept for anyone who tows a caravan, trailer, or any substantial load with their vehicle. It refers to the complex interplay of weights and balances between the tow vehicle and the towed unit, ensuring a safe, stable, and legal journey. Failing to understand and adhere to these limits can lead to dangerous driving conditions, vehicle damage, and significant legal repercussions. This guide delves deep into what towing weight means, how to calculate it, and why it's paramount for your safety.

What is Caravan Towing Weight?

Caravan towing weight, in essence, refers to the entire system of weights involved when a vehicle tows a caravan. It's not just about the caravan's total mass, but also how that mass is distributed and how it relates to the tow vehicle's capabilities. The key components include:

  • Caravan's Maximum Authorised Mass (MAM): This is the maximum laden weight that the caravan is legally allowed to be. It's set by the manufacturer and is usually found on the caravan's VIN plate. It includes the caravan's weight plus all passengers, luggage, and water.
  • Caravan's Loaded Weight: This is the actual weight of the caravan when it's loaded up for a trip. It must always be less than or equal to the caravan's MAM.
  • Tow Vehicle's Maximum Towing Capacity: This is the maximum weight the manufacturer states the tow vehicle is legally and mechanically capable of towing. Exceeding this is dangerous and illegal.
  • Tow Vehicle's Gross Vehicle Mass (GVM) or Gross Combination Mass (GCM): GVM is the maximum total weight of the vehicle itself (including passengers, fuel, and accessories). GCM is the maximum allowable total weight of the tow vehicle and the trailer combined. Often, the GCM is the more restrictive limit.
  • Nose Weight: This is the downward force exerted by the caravan's hitch onto the tow vehicle's tow ball. A correctly loaded caravan will have a nose weight that contributes to stability. It must be within the limits specified by both the caravan manufacturer and the tow vehicle manufacturer.

Who should use a caravan towing weight calculator? Anyone planning to tow a caravan, motorhome, or any trailer should use a towing weight calculator. This includes seasoned caravanners and beginners alike. It's essential for ensuring legal compliance, vehicle longevity, and, most importantly, the safety of yourself, your passengers, and other road users. It helps prevent common issues like snaking, fishtailing, and loss of control.

Common misconceptions about caravan towing weight:

  • "My car can tow anything because it's powerful." Power is only one factor. A vehicle's chassis, suspension, brakes, and transmission are equally important, as are its legal weight ratings (MAM, GCM).
  • "As long as the caravan is under its MAM, I'm fine." You must also consider the tow vehicle's towing capacity and the combined weight limits (GCM).
  • "Nose weight doesn't matter much." Incorrect nose weight is a primary cause of instability. Too little and the caravan can sway; too much can overwhelm the tow vehicle's rear suspension and steering.
  • "Towing capacity is the same as the vehicle's MAM." MAM is the vehicle's own weight limit. Towing capacity is what it can pull *in addition* to its own weight, and is often limited by GCM.

Caravan Towing Weight Formula and Mathematical Explanation

The caravan towing weight calculator utilizes several key formulas to assess the safety of your towing setup. The primary goal is to ensure that the loaded caravan's weight does not exceed the tow vehicle's capabilities and that the weight distribution (nose weight) is appropriate for stability.

1. Towing Ratio (or Towing Match): This checks how the loaded caravan's weight relates to the tow vehicle's maximum towing capacity. A commonly recommended threshold is that the caravan's loaded weight should not exceed 85% of the tow vehicle's towing capacity, though some may allow up to 100% if the vehicle is specifically designed for heavy towing and GCM is not exceeded. A lower ratio generally indicates better stability and less strain on the tow vehicle.

Formula:

Towing Ratio (%) = (Caravan Loaded Weight / Tow Vehicle's Maximum Towing Capacity) * 100

2. Nose Weight Ratio: This assesses if the caravan's actual nose weight is within the manufacturer's recommended range relative to the caravan's loaded weight. A nose weight that is too low can lead to snaking, while one that is too high can cause the rear of the tow vehicle to dip excessively, affecting handling and steering.

Formula:

Nose Weight Ratio (%) = (Caravan Actual Nose Weight / Caravan Loaded Weight) * 100

A generally accepted optimal range is between 5% and 7% of the caravan's loaded weight. Some manufacturers may specify slightly different ranges, so always check your caravan's manual.

3. Nose Weight Limit Check: This is a critical safety check to ensure the caravan's actual nose weight does not exceed the maximum specified by the tow vehicle manufacturer.

Condition:

Caravan Actual Nose Weight ≤ Tow Vehicle's Maximum Nose Weight

4. Weight Difference (or Remaining Capacity): This calculates how much more weight the tow vehicle can theoretically handle before reaching its maximum towing capacity. While the towing ratio is often more practical, this gives a raw figure.

Formula:

Weight Difference (kg) = Tow Vehicle's Maximum Towing Capacity – Caravan Loaded Weight

5. Gross Combination Mass (GCM) Check: While not directly calculated by simple input fields, it's vital to understand. GCM is the absolute maximum permitted weight of the fully loaded tow vehicle AND the fully loaded caravan together. Many modern vehicles, especially those with automatic transmissions, have a GCM limit that is reached before the towing capacity limit. You must ensure: Tow Vehicle GVM + Caravan Loaded Weight ≤ Tow Vehicle GCM.

Towing Weight Variables
Variable Meaning Unit Typical Range / Guideline
Caravan MAM Maximum Authorised Mass of the caravan. kg 1000 – 3000+
Caravan Loaded Weight Actual weight of the caravan with all equipment and supplies. kg Up to Caravan MAM
Tow Vehicle Max Towing Capacity Maximum weight the vehicle can tow. kg 500 – 3500+ (depends heavily on vehicle type)
Tow Vehicle Max Nose Weight Maximum vertical load on the tow ball. kg 50 – 150+ (depends heavily on vehicle type)
Caravan Actual Nose Weight Actual vertical load from the caravan hitch. kg 5% – 7% of Caravan Loaded Weight is ideal
Towing Ratio Comparison of loaded caravan weight to tow vehicle capacity. % Optimal: < 85%; Maximum: ≤ 100% (check vehicle specs)
Nose Weight Ratio Comparison of caravan nose weight to its loaded weight. % Optimal: 5% – 7%; Acceptable: 4% – 10% (check manuals)
Weight Difference Remaining towing capacity of the vehicle. kg Positive value indicates remaining capacity.

Practical Examples (Real-World Use Cases)

Example 1: A Well-Matched Setup

Scenario: Sarah is planning a trip with her family and their Elddis Affinity caravan. She wants to ensure her Audi Q5 is a suitable tow vehicle.

  • Elddis Affinity Caravan MAM: 1600 kg
  • Sarah loads the caravan to: 1450 kg (Caravan Loaded Weight)
  • She loads the caravan so the nose weight is: 90 kg (Caravan Actual Nose Weight)
  • Her Audi Q5 has a Maximum Towing Capacity: 2400 kg
  • Her Audi Q5 has a Maximum Nose Weight: 100 kg

Calculations using the calculator:

  • Towing Ratio: (1450 kg / 2400 kg) * 100 = 60.4% (Well within the 85% guideline)
  • Nose Weight Ratio: (90 kg / 1450 kg) * 100 = 6.2% (Within the ideal 5-7% range)
  • Nose Weight Limit Check: 90 kg (Caravan Actual) ≤ 100 kg (Vehicle Max) (Passes)
  • Weight Difference: 2400 kg – 1450 kg = 950 kg (Ample remaining capacity)

Interpretation: This is a safe and well-matched setup. The caravan's loaded weight is comfortably within the Audi Q5's towing capacity, and the nose weight is ideal for stability. Sarah can tow with confidence.

Example 2: A Potentially Unsafe Setup

Scenario: Mark is using his older Ford Focus to tow a slightly heavier Sprite Alpine caravan for a weekend away. He hasn't weighed it carefully.

  • Sprite Alpine Caravan MAM: 1300 kg
  • Mark estimates the caravan is loaded to: 1200 kg (Caravan Loaded Weight)
  • He guesses the nose weight is: 40 kg (Caravan Actual Nose Weight)
  • His Ford Focus has a Maximum Towing Capacity: 1500 kg
  • His Ford Focus has a Maximum Nose Weight: 75 kg

Calculations using the calculator:

  • Towing Ratio: (1200 kg / 1500 kg) * 100 = 80% (Within the 85% guideline, but getting close)
  • Nose Weight Ratio: (40 kg / 1200 kg) * 100 = 3.3% (Below the recommended 5% minimum)
  • Nose Weight Limit Check: 40 kg (Caravan Actual) ≤ 75 kg (Vehicle Max) (Passes)
  • Weight Difference: 1500 kg – 1200 kg = 300 kg (Remaining capacity is tight)

Interpretation: While the towing ratio is technically acceptable and the nose weight is within the vehicle's limit, the low nose weight ratio (3.3%) is a significant concern. This suggests the caravan is tail-heavy or poorly loaded, making it prone to dangerous snaking, especially at higher speeds or during gusts of wind. Mark should re-evaluate his loading, adding weight (like water or heavier items) towards the front of the caravan to achieve a better nose weight distribution (closer to 60-80kg).

How to Use This Caravan Towing Weight Calculator

Using our caravan towing weight calculator is straightforward and essential for safe travels. Follow these simple steps:

  1. Gather Your Vehicle and Caravan Specifications: You'll need accurate figures for:
    • Your caravan's Maximum Authorised Mass (MAM) – usually found on the caravan's VIN plate.
    • Your caravan's actual loaded weight (best determined by using a weighbridge).
    • Your caravan's actual nose weight (use a nose weight gauge or a bathroom scale under the hitch).
    • Your tow vehicle's maximum towing capacity (check your vehicle handbook or manufacturer's website).
    • Your tow vehicle's maximum nose weight (check your vehicle handbook).
  2. Enter the Data: Input each of these figures accurately into the corresponding fields in the calculator.
  3. Click 'Calculate Safety': The calculator will process the numbers using the formulas described above.
  4. Review the Results:
    • Primary Result: This will give you an immediate assessment of your towing safety. Look for clear indications of whether your setup is safe, potentially unsafe, or requires adjustment.
    • Intermediate Values: Pay close attention to the Towing Ratio, Nose Weight Ratio, and Nose Weight Limit check. These provide more detailed insights into specific areas of concern.
  5. Interpret the Advice: The calculator will provide guidance based on the results. If any ratios are outside the recommended ranges, or if the nose weight is too high or too low, it will flag this as a potential issue.
  6. Make Adjustments: If the calculator indicates a problem, you'll need to adjust your caravan's loading.
    • Too Heavy Caravan: Remove unnecessary items or distribute weight more evenly. If the issue persists, you may have an overweight caravan or an under-specced tow vehicle.
    • Incorrect Nose Weight: Load heavier items (like water containers or toolboxes) over or slightly forward of the caravan's axle. Avoid placing heavy items at the very rear or front of the caravan.
  7. Use the 'Reset' Button: If you make a mistake or want to recalculate with different figures, the reset button will return the fields to sensible defaults.
  8. Use the 'Copy Results' Button: You can copy a summary of your inputs and outputs for later reference or to share with a professional.

Decision-Making Guidance: Treat the calculator's results as a critical safety warning. A towing ratio below 85% and a nose weight ratio between 5-7% are strong indicators of a stable and safe setup. If any metric falls outside these comfortable ranges, it warrants careful consideration and likely adjustments to your caravan's load distribution. Never compromise on towing safety; it's better to be overly cautious.

Key Factors That Affect Towing Weight Results

Several factors influence the results of a caravan towing weight calculation and the overall safety of your towing experience. Understanding these can help you make better decisions:

  1. Weight Distribution within the Caravan: This is arguably the most crucial factor for stability. Placing heavy items over or near the caravan's axle, and ensuring the nose weight is correct (typically 5-7% of loaded weight), is vital. Incorrect distribution can lead to snaking and fishtailing, regardless of whether the total weight is within limits.
  2. Accuracy of Weighing: Using approximate weights can lead to a false sense of security. Caravan MAM, loaded weight, and nose weight should ideally be confirmed with weighbridges and dedicated nose weight gauges for accurate calculations. Relying on manufacturer specs alone without weighing your actual load can be misleading.
  3. Tow Vehicle's Condition and Maintenance: The performance and safety of your tow vehicle degrade with age and wear. Worn tyres, brakes, suspension, and a poorly maintained engine can significantly reduce its effective towing capability and safety margins, even if the numbers on paper look good.
  4. Type of Tow Vehicle: A large, heavy SUV or 4×4 will inherently offer more stability and capacity than a small hatchback, even if both have the same stated towing capacity. The vehicle's wheelbase, weight, and aerodynamics play a substantial role in how it handles the forces exerted by a towed caravan.
  5. External Conditions (Wind, Road Surface): Strong crosswinds, uneven road surfaces, and passing large vehicles can all exacerbate instability. A setup that feels stable in calm conditions might become dangerously unstable when these external factors come into play. This is why maintaining a good safety margin (e.g., keeping towing ratios well below maximums) is essential.
  6. Tyre Pressures (Both Vehicle and Caravan): Incorrect tyre pressures can dramatically affect handling and stability. Under-inflated tyres generate excessive heat and can lead to blowouts, while over-inflated tyres reduce the contact patch with the road, affecting grip and ride comfort. Always ensure tyres are inflated to the recommended pressures for towing.
  7. Speed: The faster you travel, the more pronounced any instability becomes. Snaking and fishtailing forces increase exponentially with speed. Driving at a safe, moderate speed appropriate for the conditions is paramount.

Frequently Asked Questions (FAQ)

Q1: What is the legal towing limit for caravans in the UK/Europe/US?

A1: Legal limits vary by country and specific vehicle regulations. In the UK, for instance, the caravan's loaded weight generally shouldn't exceed the tow vehicle's maximum towing capacity. For vehicles first used after 1997, there's also a legal requirement that the caravan's MAM must not exceed 85% of the car's kerb weight if the caravan's MAM is over 1,000kg. Always check your local regulations and vehicle handbook.

Q2: How do I find my caravan's Maximum Authorised Mass (MAM)?

A2: The MAM is a crucial figure. It's typically found on a plate or sticker located on the caravan's chassis, A-frame, or door frame. It's also usually listed in the caravan's owner's manual.

Q3: What happens if I exceed my tow vehicle's towing capacity?

A3: Exceeding the towing capacity is dangerous and illegal. It can lead to loss of control, damage to your vehicle's transmission, brakes, and chassis, void your insurance, and result in hefty fines or prosecution if you're involved in an accident.

Q4: How can I improve caravan stability if my nose weight is too low?

A4: To increase nose weight, load heavier items (like water containers, toolboxes, or heavy camping gear) over or just forward of the caravan's axle. Ensure these items are secured properly. Avoid placing heavy items at the very rear of the caravan.

Q5: Does the weight of passengers and fuel in the tow vehicle count towards the towing limit?

A5: Yes, the weight of passengers, fuel, and any accessories fitted to the tow vehicle reduce its available payload and can affect the Gross Combination Mass (GCM). You must ensure the combined weight of the loaded tow vehicle and the loaded caravan does not exceed the GCM. The towing capacity itself refers to the trailer's weight, but the vehicle's overall weight is critical.

Q6: What is the difference between MAM and MTPLM?

A6: MAM (Maximum Authorised Mass) and MTPLM (Maximum Technically Permissible Laden Mass) are essentially the same thing. They represent the maximum weight the caravan is designed to carry when fully loaded. Different manufacturers might use slightly different terminology.

Q7: Can I tow a caravan with a car that has the same towing capacity as the caravan's MAM?

A7: While technically possible if the MAM matches the towing capacity, it's generally not recommended for optimal safety and stability. A buffer is always advisable. Also, consider the 85% rule if applicable (for post-1997 vehicles in the UK) and the Gross Combination Mass (GCM) of the vehicle, which might be the limiting factor.

Q8: Does driving license affect towing capacity?

A8: Yes, in many countries, your driving license category determines the maximum weight of a trailer you can legally tow. For example, in the UK, if you passed your car test before January 1, 1997, you can typically tow heavier combinations than those who passed after that date without taking an additional test. Always check current licensing laws.

© 2023 Your Website Name. All rights reserved.

Disclaimer: This calculator provides estimations for educational purposes. Always consult your vehicle and caravan manufacturer's manuals and adhere to local regulations. Professional advice should be sought for specific towing situations.

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Let's treat it as one for simplicity. errors = true; } // Display errors document.getElementById("caravanMawError").innerText = errorMessages.caravanMaw; document.getElementById("caravanLoadedWeightError").innerText = errorMessages.caravanLoadedWeight; document.getElementById("towVehicleMawError").innerText = errorMessages.towVehicleMaw; document.getElementById("towVehicleMaxNoseWeightError").innerText = errorMessages.towVehicleMaxNoseWeight; document.getElementById("caravanNoseWeightError").innerText = errorMessages.caravanNoseWeight; if (errors) { document.getElementById("resultsSection").classList.add("hidden"); return; } else { document.getElementById("resultsSection").classList.remove("hidden"); } // Calculations var towingRatio = (caravanLoadedWeight / towVehicleMaw) * 100; var noseWeightRatio = (caravanNoseWeight / caravanLoadedWeight) * 100; var weightDifference = towVehicleMaw – caravanLoadedWeight; var primaryResultMessage = ""; var primaryResultClass = ""; var isSafe = true; // Assess safety based on ratios and limits if (towingRatio > 100) { primaryResultMessage = "DANGER: Caravan OVER VEHICLE CAPACITY!"; primaryResultClass = "danger"; isSafe = false; } else if (towingRatio > 85) { primaryResultMessage = "WARNING: High Towing Ratio!"; primaryResultClass = "warning"; isSafe = false; } if (caravanNoseWeight > towVehicleMaxNoseWeight) { primaryResultMessage = "DANGER: Nose Weight EXCEEDS VEHICLE LIMIT!"; primaryResultClass = "danger"; isSafe = false; } else if (noseWeightRatio 10) { // Slightly wider acceptable range than ideal 5-7% if (primaryResultMessage) primaryResultMessage += " AND "; primaryResultMessage += "WARNING: Nose Weight Ratio outside optimal range!"; primaryResultClass = "warning"; isSafe = false; } if (caravanLoadedWeight > caravanMaw) { if (primaryResultMessage) primaryResultMessage += " AND "; primaryResultMessage += "DANGER: Caravan Loaded Weight EXCEEDS MAM!"; primaryResultClass = "danger"; isSafe = false; } if (isSafe && !primaryResultMessage) { primaryResultMessage = "SAFE SETUP"; primaryResultClass = "safe"; } else if (!primaryResultMessage) { // Catch-all if no specific danger found but issues exist primaryResultMessage = "ADJUSTMENTS RECOMMENDED"; primaryResultClass = "warning"; } document.getElementById("primaryResult").innerText = primaryResultMessage; document.getElementById("primaryResult").className = "primary-result " + primaryResultClass; // Apply class for styling document.getElementById("towingRatio").innerText = towingRatio.toFixed(1) + "%"; document.getElementById("noseWeightRatio").innerText = noseWeightRatio.toFixed(1) + "%"; document.getElementById("weightDifference").innerText = weightDifference.toFixed(0) + " kg"; // Update copy result elements document.getElementById("copyPrimaryResult").innerText = primaryResultMessage; document.getElementById("copyTowingRatio").innerText = towingRatio.toFixed(1) + "%"; document.getElementById("copyNoseWeightRatio").innerText = noseWeightRatio.toFixed(1) + "%"; document.getElementById("copyWeightDifference").innerText = weightDifference.toFixed(0) + " kg"; document.getElementById("copyCaravanMaw").innerText = caravanMaw.toFixed(0); document.getElementById("copyCaravanLoadedWeight").innerText = caravanLoadedWeight.toFixed(0); document.getElementById("copyTowVehicleMaw").innerText = towVehicleMaw.toFixed(0); document.getElementById("copyTowVehicleMaxNoseWeight").innerText = towVehicleMaxNoseWeight.toFixed(0); document.getElementById("copyCaravanNoseWeight").innerText = caravanNoseWeight.toFixed(0); updateChart(towingRatio, noseWeightRatio, caravanNoseWeight, towVehicleMaxNoseWeight); } function resetCalculator() { document.getElementById("caravanMaw").value = "1800"; document.getElementById("caravanLoadedWeight").value = "1500"; document.getElementById("towVehicleMaw").value = "2000"; // Vehicle Max Towing Capacity document.getElementById("towVehicleMaxNoseWeight").value = "100"; document.getElementById("caravanNoseWeight").value = "90"; // Clear errors var errorElements = document.querySelectorAll('.error-message'); for (var i = 0; i < errorElements.length; i++) { errorElements[i].innerText = ''; } document.getElementById("resultsSection").classList.add("hidden"); calculateTowingSafety(); // Recalculate with defaults } function copyResults() { var copyDiv = document.getElementById("resultsToCopy"); var hiddenTextarea = document.createElement("textarea"); hiddenTextarea.style.position = "absolute"; hiddenTextarea.style.left = "-9999px"; hiddenTextarea.value = copyDiv.innerText; document.body.appendChild(hiddenTextarea); hiddenTextarea.select(); try { document.execCommand("copy"); alert("Results copied to clipboard!"); } catch (err) { console.error("Could not copy text: ", err); alert("Failed to copy results."); } document.body.removeChild(hiddenTextarea); } function updateChart(towingRatio, noseWeightRatio, caravanNoseWeight, towVehicleMaxNoseWeight) { var ctx = document.getElementById('stabilityChart').getContext('2d'); // Destroy previous chart instance if it exists if (window.myTowingChart) { window.myTowingChart.destroy(); } // Define chart parameters var xAxisData = [ { value: 0, label: 'Min Nose Weight' }, { value: 5, label: '5%' }, { value: 7, label: '7%' }, { value: 10, label: '10% Max' }, { value: 15, label: 'Excessive' } ]; var optimalRangeMin = 5; var optimalRangeMax = 7; var warningRangeMin = 4; var warningRangeMax = 10; var stabilityData = []; var caravanNoseWeightPercent = caravanNoseWeight / parseFloat(document.getElementById("caravanLoadedWeight").value) * 100; // Generate data points for the chart based on nose weight percentage // Simulate stability zones for (var i = 0; i < xAxisData.length; i++) { var percent = xAxisData[i].value; var stabilityLevel = 'Optimal Stability'; // Default if (percent warningRangeMax) { stabilityLevel = 'Potential Instability (too high nose weight)'; } else if (percent > optimalRangeMax) { stabilityLevel = 'Acceptable (approaching high)'; } else if (percent =0 && Math.round(caravanNoseWeightPercent) <= 15) { stabilityData.push({ x: percent, y: 1, label: 'Actual Nose Weight', marker: '●', markerColor: '#004a99' }); } else { // Basic representation of stability zones var yValue = 0; // Base level if (stabilityLevel === 'Optimal Stability') yValue = 1; else if (stabilityLevel.includes('Instability')) yValue = 0.5; else yValue = 0.75; // Acceptable range stabilityData.push({ x: percent, y: yValue, label: stabilityLevel }); } } // Visualize the actual nose weight percentage var actualNoseWeightValue = Math.round(caravanNoseWeightPercent); var actualNoseWeightColor = '#004a99'; // Default to good var actualNoseWeightLabel = 'Actual Nose Weight'; if (actualNoseWeightValue warningRangeMax) { actualNoseWeightColor = '#d9534f'; // Red for high actualNoseWeightLabel += ' (High)'; } else { actualNoseWeightColor = '#5cb85c'; // Green for optimal actualNoseWeightLabel += ' (Optimal)'; } // Check if actual nose weight is within vehicle limit if (caravanNoseWeight > towVehicleMaxNoseWeight) { actualNoseWeightColor = '#d9534f'; // Definitely red if over vehicle limit actualNoseWeightLabel = 'Actual Nose Weight (EXCEEDS VEHICLE LIMIT!)'; } // Create the chart window.myTowingChart = new Chart(ctx, { type: 'bar', // Using bar chart for better visualization of zones data: { labels: xAxisData.map(item => item.label), datasets: [ { label: 'Stability Zones', data: stabilityData.map(d => d.y), // Y values represent zones backgroundColor: stabilityData.map(d => { if (d.label.includes('Optimal')) return 'rgba(40, 167, 69, 0.6)'; // Green for optimal if (d.label.includes('Instability')) return 'rgba(220, 53, 69, 0.6)'; // Red for instability return 'rgba(255, 193, 7, 0.6)'; // Yellow for acceptable but not optimal }), borderColor: stabilityData.map(d => { if (d.label.includes('Optimal')) return 'rgba(40, 167, 69, 1)'; if (d.label.includes('Instability')) return 'rgba(220, 53, 69, 1)'; return 'rgba(255, 193, 7, 1)'; }), borderWidth: 1, order: 2 // Draw stability zones behind the marker }, { label: actualNoseWeightLabel, data: Array(xAxisData.length).fill(null).map((_, i) => { var percent = xAxisData[i].value; // Draw a marker only at the position corresponding to the actual nose weight % return (Math.abs(percent – actualNoseWeightValue) < 0.1) ? 1.1 : null; // Slightly above bars }), type: 'scatter', // Use scatter to plot a single point backgroundColor: actualNoseWeightColor, borderColor: actualNoseWeightColor, pointRadius: 10, pointHoverRadius: 12, order: 1 // Draw marker on top } ] }, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: true, max: 1.2, // Give a little space above the marker ticks: { display: false // Hide Y-axis ticks as they represent zones }, grid: { display: false // Hide Y-axis grid lines } }, x: { title: { display: true, text: 'Nose Weight as % of Loaded Caravan Weight' } } }, plugins: { legend: { display: true, labels: { generateLabels: function(chart) { var labels = Chart.defaults.plugins.legend.labels.generateLabels(chart); // Customizing labels for clarity labels.forEach(function(label) { if (label.text.includes('Stability Zones')) { label.text = 'Stability Zones'; } else if (label.text.includes('Actual Nose Weight')) { label.text = actualNoseWeightLabel; // Use dynamic label } }); return labels; } } }, tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || ''; if (label) { label += ': '; } if (context.datasetIndex === 0) { // Stability Zones dataset var stabilityText = context.raw; if (stabilityText === 1) return 'Optimal Stability (5-7%)'; if (stabilityText === 0.5) return 'Potential Instability'; if (stabilityText === 0.75) return 'Acceptable Range'; return label + stabilityText; } else if (context.datasetIndex === 1) { // Actual Nose Weight dataset return actualNoseWeightLabel + ' (' + actualNoseWeightValue + '%)'; } return label; } } } } } }); } // Event listeners document.getElementById("calculateBtn").addEventListener("click", calculateTowingSafety); document.getElementById("resetBtn").addEventListener("click", resetCalculator); document.getElementById("copyBtn").addEventListener("click", copyResults); // Initial calculation on page load document.addEventListener("DOMContentLoaded", function() { resetCalculator(); // Load with default values and calculate }); // Add event listeners for real-time updates on input changes var inputFields = document.querySelectorAll('.loan-calc-container input[type="number"], .loan-calc-container select'); for (var i = 0; i < inputFields.length; i++) { inputFields[i].addEventListener("input", calculateTowingSafety); }

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