Calculating Weight of Trailer You Can Tow

Determine the maximum weight your vehicle can safely tow.

Towing Capacity Inputs

Enter the specifications for your vehicle and trailer to calculate your safe towing weight.

Towing Capacity Factors & Limits

Factor	Description	Unit	Value
Vehicle Curb Weight	Weight of the empty vehicle.	lbs	—
Vehicle Cargo & Passenger Weight	Weight added to the vehicle.	lbs	—
Vehicle Gross Vehicle Weight (GVW)	Curb Weight + Cargo/Passenger Weight.	lbs	—
Vehicle Gross Vehicle Weight Rating (GVWR)	Maximum allowed weight for the vehicle itself.	lbs	—
Vehicle Gross Combined Weight Rating (GCWR)	Maximum allowed weight for vehicle + trailer.	lbs	—
Trailer Tongue Weight %	Percentage of trailer weight on the hitch.	%	—
Maximum Allowable Trailer Weight (GCWR Limit)	GCWR – GVW. The absolute maximum trailer weight.	lbs	—
Available Payload for Tongue Weight	GVWR – GVW. Max weight the hitch can support.	lbs	—

Towing limits comparison based on GCWR and payload constraints.

What is Towing Capacity?

Towing capacity refers to the maximum weight a vehicle is designed and rated to safely pull. It's a crucial specification for anyone planning to tow a trailer, whether for recreational purposes like camping or boating, or for work-related hauling. Understanding your vehicle's towing capacity is paramount for safety, preventing damage to your vehicle, and ensuring legal compliance on the road. It's not just about horsepower; it involves a complex interplay of the vehicle's frame, suspension, brakes, engine cooling, and transmission.

Who should use this information? Anyone who owns or is considering purchasing a vehicle that will be used for towing. This includes owners of SUVs, pickup trucks, vans, and even some cars equipped with towing packages. It's also vital for those buying a trailer – you must ensure your tow vehicle can handle the trailer's loaded weight.

Common Misconceptions:

• "My truck is big, so it can tow anything." Vehicle size is only one factor. The specific ratings (GVWR, GCWR) are the definitive limits.
• "Towing capacity is just the trailer weight." It's the *loaded* trailer weight, including any equipment, water, or cargo inside it.
• "Horsepower is all that matters." While important for acceleration, brakes, suspension, and frame strength are critical for safe towing, especially at higher speeds and under load.
• "The number on the hitch is the towing capacity." The hitch rating is important, but it's only one component. The vehicle's official ratings are the ultimate limits.

Towing Capacity Formula and Mathematical Explanation

Calculating the precise towing capacity involves understanding several key ratings found on your vehicle's door jamb sticker or owner's manual. The core principle is that the combined weight of your vehicle and trailer must never exceed the vehicle's Gross Combined Weight Rating (GCWR), and the weight on your vehicle's axles must not exceed its Gross Vehicle Weight Rating (GVWR).

Here's a breakdown of the primary factors:

• Gross Vehicle Weight Rating (GVWR): The maximum loaded weight of the vehicle itself, including passengers, cargo, and the tongue weight of the trailer.
  GVWR = Curb Weight + Passenger Weight + Cargo Weight + Trailer Tongue Weight
• Gross Vehicle Weight (GVW): The actual current weight of the loaded vehicle.
  GVW = Curb Weight + Passenger Weight + Cargo Weight
• Available Payload for Tongue Weight: The difference between GVWR and GVW indicates how much more weight your vehicle can safely carry on its frame, which includes the trailer's tongue weight.
  Available Payload for Tongue Weight = GVWR - GVW
• Trailer Tongue Weight: This is the downward force exerted by the trailer hitch onto the vehicle's hitch receiver. It's typically estimated as 10% to 15% of the trailer's total loaded weight.
  Trailer Tongue Weight = Trailer's Loaded Weight * (Tongue Weight Percentage / 100)
• Gross Combined Weight Rating (GCWR): The maximum total weight of the fully loaded vehicle AND the fully loaded trailer. This is often the most significant limiting factor.
  GCWR = GVW + Trailer's Loaded Weight

Primary Calculation Steps:

1. Calculate Current Vehicle Gross Weight (GVW): Sum the vehicle's curb weight and the weight of all passengers and cargo.
2. Calculate Available Payload for Tongue Weight: Subtract the current GVW from the vehicle's GVWR. This tells you the maximum weight your hitch can support.
3. Calculate Maximum Trailer Tongue Weight: Use the Available Payload for Tongue Weight calculated in step 2.
4. Calculate Maximum Trailer Weight based on Tongue Weight: Divide the Maximum Trailer Tongue Weight by the expected tongue weight percentage (e.g., divide by 0.15 for 15%).
   Max Trailer Weight (Payload Limit) = Available Payload for Tongue Weight / (Tongue Weight Percentage / 100)
5. Calculate Maximum Trailer Weight based on GCWR: Subtract the current GVW from the vehicle's GCWR. This is the absolute maximum weight the trailer can be.
   Max Trailer Weight (GCWR Limit) = GCWR - GVW
6. Determine the Limiting Factor: The actual maximum trailer weight you can tow is the *lesser* of the two calculated maximums (from step 4 and step 5).

Variables Table:

Variable	Meaning	Unit	Typical Range
Vehicle Curb Weight	Weight of the vehicle itself, fully serviced.	lbs	1500 – 7000+
Passenger & Cargo Weight	Weight of occupants, pets, luggage, gear.	lbs	100 – 1000+
GVWR	Gross Vehicle Weight Rating (max vehicle weight).	lbs	2500 – 11000+
GCWR	Gross Combined Weight Rating (max vehicle + trailer weight).	lbs	4000 – 25000+
Trailer Tongue Weight %	Percentage of trailer weight resting on the hitch.	%	10 – 15%
Trailer's Loaded Weight	The total weight of the trailer including its contents.	lbs	1000 – 15000+
Available Payload	Weight capacity remaining on the vehicle for passengers, cargo, and tongue weight.	lbs	Varies widely

Practical Examples (Real-World Use Cases)

Example 1: Family SUV Towing a Camper

A family is planning a road trip with their SUV and a travel trailer. They need to ensure they are within safe towing limits.

• Vehicle: Mid-size SUV
• Vehicle Curb Weight: 4,800 lbs
• Passengers & Cargo: 2 adults + 2 children + gear = 700 lbs
• Vehicle GVWR: 6,500 lbs
• Vehicle GCWR: 11,500 lbs
• Desired Trailer Tongue Weight %: 13%

Calculation Steps:

1. GVW: 4,800 lbs (Curb) + 700 lbs (Cargo) = 5,500 lbs
2. Available Payload for Tongue Weight: 6,500 lbs (GVWR) – 5,500 lbs (GVW) = 1,000 lbs
3. Max Trailer Tongue Weight: 1,000 lbs
4. Max Trailer Weight (Payload Limit): 1,000 lbs / (13 / 100) = 1000 / 0.13 ≈ 7,692 lbs
5. Max Trailer Weight (GCWR Limit): 11,500 lbs (GCWR) – 5,500 lbs (GVW) = 6,000 lbs
6. Limiting Factor: The GCWR limit (6,000 lbs) is lower than the payload limit (7,692 lbs).

Result: The family can safely tow a trailer weighing up to 6,000 lbs. They should look for a travel trailer with a Gross Vehicle Weight Rating (GVWR) of 6,000 lbs or less.

Example 2: Work Truck Towing a Equipment Trailer

A contractor is using their pickup truck to haul a trailer with construction equipment.

• Vehicle: Heavy-duty Pickup Truck
• Vehicle Curb Weight: 6,000 lbs
• Passengers & Cargo: 1 driver + tools/equipment = 500 lbs
• Vehicle GVWR: 9,000 lbs
• Vehicle GCWR: 18,000 lbs
• Trailer Tongue Weight %: 15%

Calculation Steps:

1. GVW: 6,000 lbs (Curb) + 500 lbs (Cargo) = 6,500 lbs
2. Available Payload for Tongue Weight: 9,000 lbs (GVWR) – 6,500 lbs (GVW) = 2,500 lbs
3. Max Trailer Tongue Weight: 2,500 lbs
4. Max Trailer Weight (Payload Limit): 2,500 lbs / (15 / 100) = 2500 / 0.15 ≈ 16,667 lbs
5. Max Trailer Weight (GCWR Limit): 18,000 lbs (GCWR) – 6,500 lbs (GVW) = 11,500 lbs
6. Limiting Factor: The GCWR limit (11,500 lbs) is lower than the payload limit (16,667 lbs).

Result: The contractor can safely tow a trailer weighing up to 11,500 lbs. This is a crucial number for selecting the right equipment trailer and ensuring the loaded weight of the trailer and its contents does not exceed this limit.

How to Use This Towing Capacity Calculator

Using this calculator is straightforward. Follow these steps to quickly determine your safe towing limits:

1. Gather Your Vehicle's Specifications: You'll need the following information, usually found on a sticker inside the driver's doorjamb or in your owner's manual:
   • Vehicle Curb Weight
   • Vehicle Gross Vehicle Weight Rating (GVWR)
   • Vehicle Gross Combined Weight Rating (GCWR)
2. Estimate Your Load: Determine the weight of passengers, pets, and any cargo you typically carry inside your vehicle.
3. Set Trailer Tongue Weight Percentage: Input the expected tongue weight percentage for your trailer. 15% is a common and safe starting point for most conventional trailers.
4. Enter the Data: Input the gathered numbers into the corresponding fields in the calculator.
5. Calculate: Click the "Calculate" button.

How to Read the Results:

• Primary Result (Max Trailer Weight): This is the most critical number. It represents the maximum weight your trailer can have (when fully loaded) without exceeding your vehicle's GCWR or GVWR limitations, considering your current vehicle load and tongue weight percentage.
• Available Payload: Shows how much weight capacity remains on your vehicle for passengers, cargo, and tongue weight. If this number is low, it might limit your trailer size even if your GCWR is high.
• Max Trailer Tongue Weight: The maximum weight the hitch can safely support based on your vehicle's GVWR and current load.
• Max Trailer Weight (GCWR Limit): The maximum trailer weight allowed based solely on the GCWR, assuming your vehicle is loaded to its GVW.

Decision-Making Guidance:

Always use the *lowest* calculated maximum trailer weight as your definitive safe towing limit. If the GCWR limit is lower than the payload limit, you must adhere to the GCWR. Conversely, if the payload limit is lower, that becomes your constraint. This calculator helps identify the bottleneck, ensuring you don't overload your vehicle in any respect. When in doubt, consult your vehicle manufacturer or a qualified professional.

Key Factors That Affect Towing Capacity Results

Several elements significantly influence your vehicle's actual towing capacity and the safe weight you can pull. Understanding these can help you make informed decisions:

1. Vehicle Specifications (GVWR & GCWR):

   These are the absolute limits set by the manufacturer. The GVWR restricts the weight on the vehicle's axles (including tongue weight), while the GCWR limits the combined weight of the tow vehicle and trailer. Exceeding either rating is dangerous and can cause catastrophic failure.

2. Vehicle Load (GVW):

   Every pound of passenger or cargo weight inside your vehicle reduces the amount of weight available for the trailer's tongue. If you consistently carry heavy loads, your effective towing capacity diminishes significantly.

3. Trailer Tongue Weight Percentage:

   A higher tongue weight (e.g., 15%) puts more stress on the vehicle's rear suspension and hitch. While crucial for trailer stability, it directly consumes your available payload. Using an estimate that's too low might lead you to overload your hitch's capacity.

4. Tire Load Rating:

   Your vehicle's tires must be rated to carry the load. Ensure they are properly inflated and match or exceed the load requirements for your vehicle's GVWR. Overloaded or underinflated tires are a major safety hazard.

5. Hitch Rating:

   The trailer hitch receiver and ball mount must be rated to handle the trailer's weight and tongue weight. While the vehicle's ratings are primary, a hitch that's too weak is a critical failure point.

6. Braking System:

   The trailer's brakes (if equipped and required by law) are vital for safe stopping distances. Your vehicle's brakes must also be in excellent condition to handle the additional load. Ensure your vehicle's brake system is up to the task.

7. Engine Cooling and Transmission:

   Towing puts a significant strain on these systems. Vehicles with "towing packages" often have upgraded radiators and transmission coolers to prevent overheating, especially in demanding conditions like climbing hills or in hot weather.

8. Driving Conditions and Terrain:

   Towing capacity ratings are typically for ideal, level road conditions. Steep grades, high altitudes, strong headwinds, and adverse weather significantly increase the stress on your vehicle and reduce its effective safe towing ability.

Frequently Asked Questions (FAQ)

Q1: What is the difference between GVWR and GCWR?

GVWR (Gross Vehicle Weight Rating) is the maximum weight your vehicle alone can be, including passengers, cargo, and tongue weight. GCWR (Gross Combined Weight Rating) is the maximum weight your vehicle *and* its trailer can be together.

Q2: How accurate is the trailer tongue weight percentage?

The 10-15% rule is a guideline. Heavier trailers or trailers with specific load distributions might require a different percentage. Always check the trailer manufacturer's recommendations and aim for stable towing dynamics.

Q3: Can I tow a trailer heavier than my vehicle's curb weight?

Yes, in most cases. Your vehicle's towing capacity is determined by its GVWR and GCWR, not just its curb weight. As long as the total combined weight (vehicle + loaded trailer) is below the GCWR and the vehicle's loaded weight is below its GVWR, you should be within limits.

Q4: What happens if I exceed my towing capacity?

Exceeding towing capacity can lead to serious safety risks, including brake failure, loss of control, tire blowouts, and severe damage to your vehicle's engine, transmission, suspension, and frame. It can also void your insurance and warranties.

Q5: Does a "tow package" increase my vehicle's towing capacity?

Often, yes. A tow package typically includes components like a heavier-duty radiator, transmission cooler, upgraded alternator, and trailer wiring harness, which enable the vehicle to safely handle the stresses of towing up to its rated capacity. It doesn't usually increase the fundamental GVWR or GCWR unless specified by the manufacturer.

Q6: How do I find my vehicle's curb weight?

Curb weight is usually listed in the vehicle's owner's manual or on a sticker inside the driver's doorjamb. If unavailable, you can get your vehicle weighed at a certified scale station.

Q7: What is the difference between trailer GVWR and its actual weight?

The trailer's GVWR is the maximum weight the trailer itself is designed to carry. Its actual weight is the current weight of the trailer and its contents. You must ensure the trailer's *actual loaded weight* does not exceed the towing capacity calculated for your vehicle, and that the trailer's GVWR is also not exceeded.

Q8: Can I tow a trailer with electric brakes if my vehicle doesn't have a brake controller?

No. Most trailers over a certain weight (e.g., 1500-3000 lbs, depending on local regulations) require their own braking system. To utilize these electric brakes, your tow vehicle needs a properly installed and adjusted trailer brake controller.

var vehicleCurbWeightInput = document.getElementById('vehicleCurbWeight'); var cargoWeightInput = document.getElementById('cargoWeight'); var tongueWeightPercentageInput = document.getElementById('tongueWeightPercentage'); var gvwrInput = document.getElementById('gvwr'); var gcvwrInput = document.getElementById('gcvwr'); var maxTrailerWeightDisplay = document.getElementById('maxTrailerWeight'); var availablePayloadDisplay = document.getElementById('availablePayload'); var maxTongueWeightDisplay = document.getElementById('maxTongueWeight'); var maxTrailerWeightByGCWRDisplay = document.getElementById('maxTrailerWeightByGCWR'); // Table elements var tableCurbWeight = document.getElementById('tableCurbWeight'); var tableCargoWeight = document.getElementById('tableCargoWeight'); var tableGVWR = document.getElementById('tableGVWR'); var tableGCWR = document.getElementById('tableGCWR'); var tableTongueWeightPercent = document.getElementById('tableTongueWeightPercent'); var tableMaxTrailerWeightGCWR = document.getElementById('tableMaxTrailerWeightGCWR'); var tableAvailablePayloadTongue = document.getElementById('tableAvailablePayloadTongue'); var tableGVW = document.getElementById('tableGVW'); // Error message elements var vehicleCurbWeightError = document.getElementById('vehicleCurbWeightError'); var cargoWeightError = document.getElementById('cargoWeightError'); var tongueWeightPercentageError = document.getElementById('tongueWeightPercentageError'); var gvwrError = document.getElementById('gvwrError'); var gcvwrError = document.getElementById('gcvwrError'); var chart; var chartContext; function initChart() { chartContext = document.getElementById('towingCapacityChart').getContext('2d'); chart = new Chart(chartContext, { type: 'bar', data: { labels: ['Max Trailer Weight', 'GCWR Limit', 'Payload Limit'], datasets: [{ label: 'Towing Capacity (lbs)', data: [0, 0, 0], backgroundColor: [ 'rgba(0, 74, 153, 0.7)', // Primary color for Max Trailer Weight 'rgba(40, 167, 69, 0.7)', // Success color for GCWR Limit 'rgba(255, 193, 7, 0.7)' // Warning color for Payload Limit ], borderColor: [ 'rgba(0, 74, 153, 1)', 'rgba(40, 167, 69, 1)', 'rgba(255, 193, 7, 1)' ], borderWidth: 1 }] }, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: true, title: { display: true, text: 'Weight (lbs)' } } }, plugins: { legend: { display: false // Hides the legend as labels are clear }, tooltip: { callbacks: { label: function(context) { var label = context.dataset.label || "; if (label) { label += ': '; } if (context.parsed.y !== null) { label += new Intl.NumberFormat('en-US').format(context.parsed.y) + ' lbs'; } return label; } } } } } }); } function updateChart(maxTrailerWeight, maxTrailerWeightGCWR, maxTongueWeightResult) { if (chart) { // Ensure values are numbers and handle potential NaN/Infinity var safeMaxTrailer = !isNaN(maxTrailerWeight) && isFinite(maxTrailerWeight) ? maxTrailerWeight : 0; var safeGcwLimit = !isNaN(maxTrailerWeightGCWR) && isFinite(maxTrailerWeightGCWR) ? maxTrailerWeightGCWR : 0; // The 'Payload Limit' on the chart represents the Max Trailer Weight that can be towed if tongue weight is the only constraint. var safePayloadLimit = !isNaN(maxTongueWeightResult) && isFinite(maxTongueWeightResult) ? maxTongueWeightResult : 0; chart.data.datasets[0].data = [safeMaxTrailer, safeGcwLimit, safePayloadLimit]; chart.update(); } } function calculateTowingCapacity() { // Clear previous errors vehicleCurbWeightError.textContent = "; cargoWeightError.textContent = "; tongueWeightPercentageError.textContent = "; gvwrError.textContent = "; gcvwrError.textContent = "; // Get input values var vehicleCurbWeight = parseFloat(vehicleCurbWeightInput.value); var cargoWeight = parseFloat(cargoWeightInput.value); var tongueWeightPercentage = parseFloat(tongueWeightPercentageInput.value); var gvwr = parseFloat(gvwrInput.value); var gcvwr = parseFloat(gcvwrInput.value); var isValid = true; // Validate inputs if (isNaN(vehicleCurbWeight) || vehicleCurbWeight <= 0) { vehicleCurbWeightError.textContent = 'Please enter a valid vehicle curb weight.'; isValid = false; } if (isNaN(cargoWeight) || cargoWeight < 0) { // Cargo can be 0 cargoWeightError.textContent = 'Please enter a valid cargo and passenger weight.'; isValid = false; } if (isNaN(tongueWeightPercentage) || tongueWeightPercentage 100) { tongueWeightPercentageError.textContent = 'Please enter a tongue weight percentage between 1 and 100.'; isValid = false; } if (isNaN(gvwr) || gvwr <= 0) { gvwrError.textContent = 'Please enter a valid GVWR.'; isValid = false; } if (isNaN(gcvwr) || gcvwr 0) { maxTrailerWeightByPayload = maxTongueWeight / (tongueWeightPercentage / 100); } // GCWR-based calculation var maxTrailerWeightByGCWR = gcvwr – currentGvw; // Determine the overall maximum trailer weight var overallMaxTrailerWeight = Math.min(maxTrailerWeightByPayload, maxTrailerWeightByGCWR); // Ensure results are not negative (can happen if inputs are illogical, e.g., GVW > GVWR) overallMaxTrailerWeight = Math.max(0, overallMaxTrailerWeight); availablePayload = Math.max(0, availablePayload); maxTongueWeight = Math.max(0, maxTongueWeight); maxTrailerWeightByGCWR = Math.max(0, maxTrailerWeightByGCWR); // Display results maxTrailerWeightDisplay.textContent = overallMaxTrailerWeight.toLocaleString('en-US') + ' lbs'; availablePayloadDisplay.textContent = availablePayload.toLocaleString('en-US') + ' lbs'; maxTongueWeightDisplay.textContent = maxTongueWeight.toLocaleString('en-US') + ' lbs'; maxTrailerWeightByGCWRDisplay.textContent = maxTrailerWeightByGCWR.toLocaleString('en-US') + ' lbs'; // Update table updateTableValues( vehicleCurbWeight.toLocaleString('en-US'), cargoWeight.toLocaleString('en-US'), gvwr.toLocaleString('en-US'), gcvwr.toLocaleString('en-US'), tongueWeightPercentage.toLocaleString('en-US') + '%', maxTrailerWeightByGCWR.toLocaleString('en-US'), availablePayload.toLocaleString('en-US'), currentGvw.toLocaleString('en-US') ); // Update chart updateChart(overallMaxTrailerWeight, maxTrailerWeightByGCWR, maxTrailerWeightByPayload); } function updateTableValues(curbWeight, cargo, gvwrVal, gcvwrVal, tonguePercent, trailerGCWR, availPayload, currentGVW) { tableCurbWeight.textContent = curbWeight; tableCargoWeight.textContent = cargo; tableGVWR.textContent = gvwrVal; tableGCWR.textContent = gcvwrVal; tableTongueWeightPercent.textContent = tonguePercent; tableMaxTrailerWeightGCWR.textContent = trailerGCWR; tableAvailablePayloadTongue.textContent = availPayload; tableGVW.textContent = currentGVW; } function resetCalculator() { vehicleCurbWeightInput.value = "; cargoWeightInput.value = "; tongueWeightPercentageInput.value = '15'; // Sensible default gvwrInput.value = "; gcvwrInput.value = "; // Clear errors vehicleCurbWeightError.textContent = "; cargoWeightError.textContent = "; tongueWeightPercentageError.textContent = "; gvwrError.textContent = "; gcvwrError.textContent = "; // Reset results maxTrailerWeightDisplay.textContent = '– lbs'; availablePayloadDisplay.textContent = '– lbs'; maxTongueWeightDisplay.textContent = '– lbs'; maxTrailerWeightByGCWRDisplay.textContent = '– lbs'; updateTableValues('–', '–', '–', '–', '–', '–', '–', '–'); if (chart) { updateChart(0, 0, 0); } } function copyResults() { var resultsText = "— Towing Capacity Calculation Results —\n\n"; resultsText += "Primary Result:\n"; resultsText += "Maximum Safe Trailer Weight: " + maxTrailerWeightDisplay.textContent + "\n\n"; resultsText += "Key Intermediate Values:\n"; resultsText += "Available Payload for Tongue Weight: " + availablePayloadDisplay.textContent + "\n"; resultsText += "Maximum Trailer Tongue Weight: " + maxTongueWeightDisplay.textContent + "\n"; resultsText += "Maximum Trailer Weight (GCWR Limit): " + maxTrailerWeightByGCWRDisplay.textContent + "\n\n"; resultsText += "Key Assumptions & Inputs:\n"; resultsText += "Vehicle Curb Weight: " + (tableCurbWeight.textContent === '–' ? 'N/A' : tableCurbWeight.textContent) + "\n"; resultsText += "Vehicle Cargo & Passenger Weight: " + (tableCargoWeight.textContent === '–' ? 'N/A' : tableCargoWeight.textContent) + "\n"; resultsText += "Vehicle GVWR: " + (tableGVWR.textContent === '–' ? 'N/A' : tableGVWR.textContent) + "\n"; resultsText += "Vehicle GCWR: " + (tableGCWR.textContent === '–' ? 'N/A' : tableGCWR.textContent) + "\n"; resultsText += "Trailer Tongue Weight %: " + (tableTongueWeightPercent.textContent === '–' ? 'N/A' : tableTongueWeightPercent.textContent) + "\n"; resultsText += "Vehicle Current Gross Weight (GVW): " + (tableGVW.textContent === '–' ? 'N/A' : tableGVW.textContent) + "\n"; // Create a temporary textarea element to copy text var textArea = document.createElement("textarea"); textArea.value = resultsText; textArea.style.position = "fixed"; // Avoid scrolling to bottom of page in MS Edge. textArea.style.opacity = "0"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'Results copied successfully!' : 'Copying failed!'; // Display a temporary confirmation message var notification = document.createElement('div'); notification.textContent = msg; notification.style.cssText = 'position: fixed; top: 50%; left: 50%; transform: translate(-50%, -50%); background-color: #28a745; color: white; padding: 15px; border-radius: 5px; z-index: 1000; font-size: 1.1em;'; document.body.appendChild(notification); setTimeout(function(){ document.body.removeChild(notification); }, 2000); } catch (err) { console.error('Fallback: Oops, unable to copy', err); // Optionally provide a manual copy instruction here } document.body.removeChild(textArea); } // Initialize chart on page load window.onload = function() { initChart(); // Trigger calculation with default/empty values to populate tables and chart with initial '–' state calculateTowingCapacity(); }; // Add event listeners for real-time updates vehicleCurbWeightInput.addEventListener('input', calculateTowingCapacity); cargoWeightInput.addEventListener('input', calculateTowingCapacity); tongueWeightPercentageInput.addEventListener('input', calculateTowingCapacity); gvwrInput.addEventListener('input', calculateTowingCapacity); gcvwrInput.addEventListener('input', calculateTowingCapacity);