Shaft Weight Calculator

Shaft Weight Calculator: Calculate Your Golf Shaft Weight Accurately :root { –primary-color: #004a99; –secondary-color: #0056b3; –success-color: #28a745; –light-gray: #f8f9fa; –dark-gray: #343a40; –white: #ffffff; –border-color: #dee2e6; –shadow-color: rgba(0, 0, 0, 0.1); } body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: var(–light-gray); color: var(–dark-gray); line-height: 1.6; margin: 0; padding: 0; display: flex; flex-direction: column; align-items: center; min-height: 100vh; } .container { width: 100%; max-width: 980px; margin: 20px auto; padding: 25px; background-color: var(–white); border-radius: 8px; box-shadow: 0 4px 12px var(–shadow-color); display: flex; flex-direction: column; align-items: center; } h1, h2, h3 { color: var(–primary-color); text-align: center; margin-bottom: 1.5em; } h1 { font-size: 2.5em; } h2 { font-size: 1.8em; margin-top: 1.5em; } h3 { font-size: 1.4em; margin-top: 1em; } .sub-heading { font-size: 1.1em; color: #6c757d; 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Shaft Weight Calculator

Determine the ideal shaft weight for your golf clubs to optimize swing dynamics and performance.

Golf Shaft Weight Calculator

Enter the weight of the club head in grams (g). Typical drivers are 190-205g.
Enter the weight of the grip in grams (g). Standard grips are 45-65g.
Enter the shaft length in inches (in). Standard driver length is around 45 inches.
A0 A1 A2 A3 A4 B0 B1 B2 B3 B4 C0 C1 C2 C3 C4 D0 D1 D2 D3 D4 E0 E1 E2 E3 E4 Select your target swing weight. D0-D4 are common for drivers and fairway woods.

Estimated Shaft Weight Needed

— g
Target Swing Weight: —
Total Club Weight: — g
Balance Point: —
The shaft weight is estimated by working backward from the desired club total weight and swing weight, considering the head and grip weights, and shaft length. Swing weight is a measure of the club's balance, not its actual mass.

Shaft Weight vs. Total Club Weight

This chart illustrates how changes in shaft weight affect the overall total club weight, keeping other factors constant.

Key Variables and Their Impact
Variable Meaning Unit Typical Range Impact on Shaft Weight
Club Head Weight The mass of the club's head. grams (g) 180-205g (Driver) Higher head weight generally requires a lighter shaft to maintain balance or achieve a target swing weight.
Grip Weight The mass of the grip at the butt end of the shaft. grams (g) 45-65g (Standard) A heavier grip effectively 'lightens' the club at the butt end, potentially requiring a heavier shaft to compensate for balance.
Shaft Length The total length of the club shaft. inches (in) 44-46in (Driver) Longer shafts increase leverage, making the club feel lighter for a given weight. A longer shaft might necessitate a lighter shaft to achieve the same swing weight.
Target Swing Weight A measure of the club's balance point relative to its total weight. Swing Weight Units (e.g., D1) C5-D7 (Driver) This is the primary target. Achieving a specific swing weight often dictates the required shaft weight when other components are fixed.

What is Shaft Weight in Golf?

Shaft weight, in the context of golf, refers to the mass of the shaft component of a golf club. It's a critical specification that, alongside other factors like head weight, grip weight, and club length, significantly influences a golfer's swing dynamics, clubhead speed, and overall shot consistency. The shaft is the longest part of the club and acts as the primary lever during the swing. Therefore, its weight distribution and total mass play a crucial role in how the club feels and performs. Understanding and correctly selecting shaft weight is fundamental for golfers seeking to optimize their equipment for maximum performance and comfort. This shaft weight calculator is designed to help golfers and club fitters find an appropriate shaft weight based on key club specifications.

Who Should Use a Shaft Weight Calculator?

  • Golfers of all skill levels: From beginners trying to understand club components to experienced players fine-tuning their bag.
  • Club Fitters and Builders: Professionals who assemble and modify golf clubs rely on precise calculations to match golfers with the right equipment.
  • Equipment Enthusiasts: Individuals interested in the technical aspects of golf club design and performance optimization.

Common Misconceptions about Shaft Weight:

  • "Heavier is always better for power": Not necessarily. While a heavier shaft can help some players maintain control and stability, it can also reduce swing speed for others. The optimal weight is player-dependent.
  • "Shaft weight is the same as flex": Flex refers to the shaft's bending characteristics, while weight is its mass. They are distinct but related properties. A heavier shaft might be stiffer, but not always.
  • "All shafts for the same club type (e.g., driver) are interchangeable": Shafts vary significantly in weight, flex, torque, and kick point. Simply swapping one shaft for another without considering these factors can negatively impact performance. This shaft weight calculator helps isolate the weight variable.

Shaft Weight Calculation: The Mathematical Explanation

Calculating the precise shaft weight needed to achieve a specific configuration involves understanding the interplay between different club components. The goal is usually to achieve a target swing weight while controlling the total club weight. While there isn't a single, universally agreed-upon direct formula to calculate *shaft weight* in isolation without knowing the shaft's properties (like balance point), we can estimate the *required total club weight* and infer the shaft's contribution.

The core concept revolves around swing weight, which is a measure of how heavy the club *feels* to the golfer, not its absolute mass. Swing weight is measured on a logarithmic scale (e.g., D1, C3) and is determined by the distribution of weight along the club's length. The formula for swing weight is:

Swing Weight = (Club Head Weight – Grip Counterweight) * Lever Arm + Grip Counterweight

Where the Lever Arm is related to shaft length, and Grip Counterweight is a conceptual value representing the weight of the grip itself in the swing weight calculation context.

A more practical approach for estimation, especially for online calculators, often works backward from a desired total club weight and target swing weight. The total club weight is the sum of its parts:

Total Club Weight = Club Head Weight + Shaft Weight + Grip Weight + Ferrules/Adapters (often negligible)

To estimate the required shaft weight, we need to determine the total club weight that would satisfy the target swing weight. This often involves empirical data or simplified models. A common approximation used in the industry relates swing weight points to gram changes:

  • Adding 2 grams to the club head increases swing weight by 1 point.
  • Adding 2 grams to the grip (or moving it 1 inch closer to the head) decreases swing weight by 1 point.
  • Adding 1 inch to the shaft length decreases swing weight by roughly 4 points (or requires ~2g more head weight/less shaft weight for the same swing weight).

Our calculator uses a simplified model that estimates the total club weight required to hit a target swing weight, given the head weight, grip weight, and shaft length. Then, it isolates the shaft weight:

Estimated Shaft Weight = (Required Total Club Weight) – Club Head Weight – Grip Weight

The "Required Total Club Weight" is derived to satisfy the target swing weight. The "Balance Point" is also an important factor in how the club feels, often related to where the center of mass is along the shaft. A lower balance point (closer to the head) contributes to a higher swing weight.

Variable Explanations

Variable Meaning Unit Typical Range
Club Head Weight (CHW) The mass of the metal part at the end of the club. grams (g) 180-205g (Driver), 230-250g (Iron)
Grip Weight (GW) The mass of the grip material at the butt end. grams (g) 45-65g (Standard)
Shaft Length (SL) The full length of the shaft. inches (in) 44-46in (Driver), 37-39in (Iron)
Target Swing Weight (SW) A comparative measure of the club's balance. Swing Weight Units (e.g., D1) C0-E4 (varies by club type)
Estimated Shaft Weight (SWT) The calculated mass of the shaft component. grams (g) 40-80g (Graphite), 90-130g (Steel)
Total Club Weight (TCW) The sum of all components. grams (g) 280-330g (Driver), 380-450g (Iron)
Balance Point (BP) The point along the shaft where it balances, often expressed as inches from the butt or heel. inches (in) or % Varies significantly based on shaft design.

Practical Examples of Shaft Weight Calculation

Understanding the shaft weight calculator becomes clearer with real-world scenarios. Here are a couple of examples demonstrating how different inputs affect the estimated shaft weight needed.

Example 1: Standard Driver Build

A club fitter is building a driver for a golfer with a moderate swing speed. They want to achieve a common D1 swing weight.

  • Club Head Weight: 200g
  • Grip Weight: 50g
  • Shaft Length: 45 inches
  • Target Swing Weight: D1

Using the calculator:

  • The calculator might estimate a Target Total Club Weight of approximately 305g to achieve D1 swing weight with these components.
  • The Calculated Shaft Weight would then be estimated as: 305g (TCW) – 200g (CHW) – 50g (GW) = 55g.
  • The Balance Point might be calculated around 22 inches from the butt end.

Interpretation: A 55g shaft is on the lighter side, typical for graphite shafts designed for faster-swinging players or those seeking maximum clubhead speed. This weight, combined with the other components, allows the club to feel balanced at D1.

Example 2: Heavier Iron Build

A golfer wants to build a set of irons, preferring a slightly heavier feel for more control, aiming for a C8 swing weight.

  • Club Head Weight: 245g (typical for a mid-iron)
  • Grip Weight: 55g
  • Shaft Length: 38 inches (typical for a 7-iron)
  • Target Swing Weight: C8 (just below D0)

Using the calculator:

  • The calculator might estimate a Target Total Club Weight of approximately 430g to achieve C8 swing weight.
  • The Calculated Shaft Weight would then be estimated as: 430g (TCW) – 245g (CHW) – 55g (GW) = 130g.
  • The Balance Point might be calculated around 15 inches from the butt end.

Interpretation: A 130g shaft weight is typical for heavier steel shafts used in irons. This higher shaft weight, combined with the heavier head, allows for the desired C8 swing weight at a higher overall club mass, providing a more substantial feel.

These examples highlight how adjustments in component weights and length, along with the target shaft weight, significantly influence the final club configuration. The shaft weight calculator is a valuable tool for this process.

How to Use This Shaft Weight Calculator

Our Shaft Weight Calculator is designed for simplicity and accuracy, helping you estimate the ideal shaft weight for your golf clubs. Follow these steps:

  1. Enter Club Head Weight: Input the weight of your club head in grams. This is usually specified by the manufacturer.
  2. Enter Grip Weight: Input the weight of the grip you intend to use, also in grams.
  3. Enter Shaft Length: Provide the desired total length of the shaft in inches.
  4. Select Target Swing Weight: Choose your desired swing weight from the dropdown menu. Common ranges are D0-D4 for drivers and woods, and C5-D2 for irons, but this varies by player preference.
  5. Click Calculate: Press the "Calculate Shaft Weight" button.

Reading the Results:

  • Estimated Shaft Weight: This is the primary output, indicating the approximate weight (in grams) your shaft should have to meet your desired specifications. Consider available shafts in this weight range.
  • Calculated Swing Weight: This shows the resulting swing weight achieved with the estimated shaft weight.
  • Total Club Weight: The estimated total mass of the finished club.
  • Balance Point: An indicator of how the weight is distributed along the shaft, influencing feel.

Decision-Making Guidance:

Use the estimated shaft weight as a guide when selecting a shaft from manufacturers. Remember that shaft weight interacts with flex, torque, and kick point, so consider those factors too. If the calculated shaft weight falls outside typical ranges (e.g., extremely light or heavy), it might indicate an unusual combination of components or a very specific fitting requirement. Use the "Reset" button to start over, and the "Copy Results" button to save your calculated values.

This calculator is a powerful tool for anyone involved in golf club fitting and customization, helping to demystify the complex relationship between components and ultimately leading to better-performing clubs. Proper shaft weight selection is key.

Key Factors Affecting Shaft Weight Calculations

While our shaft weight calculator provides a valuable estimate, several factors influence the actual outcome and the golfer's perception of the club. Understanding these nuances is crucial for precise club fitting and building.

  1. Shaft Material & Design: The primary determinant of shaft weight is its material. Steel shafts are generally heavier (90-130g+) than graphite shafts (40-90g). Within graphite, manufacturers offer various weights targeting different player profiles. The internal design (e.g., tip thickness, wall consistency) also affects weight and performance characteristics.
  2. Target Golfer's Swing Speed: This is paramount. Faster swing speeds often benefit from lighter shafts to maximize speed, while slower swing speeds might gain stability and control from slightly heavier shafts. Our calculator uses target swing weight as a proxy, but direct correlation to swing speed is essential in fitting.
  3. Player Strength and Consistency: A physically stronger golfer might handle a heavier club and shaft without sacrificing speed. Consistency is also key; a heavier shaft can sometimes aid a player's rhythmic consistency if it feels more stable.
  4. Type of Golf Club: The calculation and target values differ significantly between drivers, fairway woods, hybrids, irons, and wedges. Drivers typically use lighter shafts (e.g., 50-70g) for speed, while irons use heavier shafts (e.g., 90-130g) for control and feel. Wedge shafts are often the heaviest.
  5. Desired Shot Shape and Trajectory: Shaft weight, along with flex and kick point, influences launch angle and spin rate. Lighter shafts combined with a lower kick point tend to produce higher trajectories, while heavier shafts with higher kick points often result in lower, more penetrating flights.
  6. Component Matching & Tolerance: Real-world component weights can vary slightly from manufacturer specifications. Experienced club builders account for these tolerances. Also, the balance point of the shaft itself significantly impacts the final swing weight and feel, which is an advanced consideration beyond simple mass calculation.
  7. Environmental Factors (Indirect): While not directly in the calculation, factors like temperature can subtly affect material properties. More importantly, a golfer's physical condition on any given day can influence how they perceive the weight and balance of a club.

Frequently Asked Questions (FAQ) about Shaft Weight

Q1: What is the standard shaft weight for a driver?

A: For drivers, standard shaft weights typically range from 50g to 70g for graphite shafts. Lighter options (40-50g) are available for faster swing speeds, and heavier options (70g+) for slower swing speeds or players seeking maximum stability.

Q2: Is a heavier shaft always better for control?

A: Not necessarily. While a heavier shaft can feel more stable and might help some players maintain control by preventing excessive head rotation, it can also decrease swing speed if the golfer struggles to accelerate it. The optimal weight depends on the individual's strength, swing mechanics, and the overall club configuration.

Q3: How does shaft weight affect my swing speed?

A: Generally, lighter shafts allow for higher potential swing speeds due to less mass to accelerate. Conversely, very heavy shafts can reduce swing speed if they are too demanding for the golfer to swing efficiently. There's an optimal shaft weight range for each golfer where they achieve maximum speed and control.

Q4: Can I change my shaft weight by changing my grip?

A: Yes, changing the grip weight will alter the total club weight and swing weight. Using a heavier grip effectively lowers the swing weight (or requires a heavier shaft/head to compensate), while a lighter grip raises it. Our shaft weight calculator accounts for grip weight.

Q5: What's the difference between shaft weight and swing weight?

A: Shaft weight is the actual mass of the shaft component (measured in grams). Swing weight is a measure of the club's balance or how heavy the club head feels during the swing (measured on a logarithmic scale like D1, C3). They are related but distinct concepts.

Q6: Should I use steel or graphite shafts?

A: Steel shafts are traditionally heavier, stiffer, and offer more feedback, making them popular for irons and wedges where control is prioritized. Graphite shafts are lighter, offering potential for increased swing speed and customization in flex and weight, often preferred for drivers and fairway woods.

Q7: My calculator result is very light/heavy. What does this mean?

A: If the calculated shaft weight is outside the typical ranges (e.g., below 40g or above 130g for common clubs), it might suggest an unconventional combination of components or a target specification that is difficult to achieve with standard options. It could also highlight a need for custom club building or re-evaluation of target specifications.

Q7: How does shaft length interact with shaft weight?

A: Shaft length significantly impacts swing weight. A longer shaft requires either a lighter shaft or a heavier head/grip to achieve the same swing weight. The calculator considers shaft length to help determine the appropriate shaft weight that balances these factors for the target swing weight.

Q8: Does shaft weight affect launch angle and spin?

A: Yes. Lighter shafts generally tend to produce higher launch angles and potentially higher spin rates, while heavier shafts often result in lower launch and spin. This is because the shaft's weight influences how the golfer loads and unloads the clubhead during the swing.

Related Tools and Internal Resources

© 2023 Your Golf Analytics. All rights reserved. | Disclaimer: This calculator provides estimates for educational purposes.

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var prefix = ""; var suffix = Math.round(swNumber % 10); // Ensure suffix is integer if (swNumber < 10) prefix = "A"; else if (swNumber < 20) prefix = "B"; else if (swNumber < 30) prefix = "C"; else if (swNumber < 40) prefix = "D"; else if (swNumber 4) { prefix = String.fromCharCode(prefix.charCodeAt(0) + Math.floor(suffix / 4)); suffix = suffix % 4; } // Ensure suffix is a single digit if (suffix 9) suffix = 9; // Should not happen with typical logic but good practice return prefix + suffix; } // Main calculation function function calculateShaftWeight() { var clubHeadWeight = parseFloat(document.getElementById("clubHeadWeight").value); var gripWeight = parseFloat(document.getElementById("gripWeight").value); var shaftLength = parseFloat(document.getElementById("shaftLength").value); var swingWeightTargetString = document.getElementById("swingWeightTarget").value; var clubHeadWeightError = document.getElementById("clubHeadWeightError"); var gripWeightError = document.getElementById("gripWeightError"); var shaftLengthError = document.getElementById("shaftLengthError"); var swingWeightTargetError = document.getElementById("swingWeightTargetError"); // Reset errors clubHeadWeightError.textContent = ""; clubHeadWeightError.classList.remove("visible"); gripWeightError.textContent = ""; gripWeightError.classList.remove("visible"); shaftLengthError.textContent = ""; shaftLengthError.classList.remove("visible"); swingWeightTargetError.textContent = ""; swingWeightTargetError.classList.remove("visible"); var isValid = true; // Validate inputs if (isNaN(clubHeadWeight) || clubHeadWeight <= 0) { clubHeadWeightError.textContent = "Please enter a valid positive number for club head weight."; clubHeadWeightError.classList.add("visible"); isValid = false; } if (isNaN(gripWeight) || gripWeight <= 0) { gripWeightError.textContent = "Please enter a valid positive number for grip weight."; gripWeightError.classList.add("visible"); isValid = false; } if (isNaN(shaftLength) || shaftLength 40) { // Estimate target total club weight based on swing weight and length. // This formula is derived from common club fitting data. var targetTCWEstimate = clubHeadWeight + gripWeight + 60; // Base guess for shaft + buffer targetTCWEstimate += (swingWeightTargetNum – 30) * 1.5; // Adjust for SW (D1=30) – driver focus targetTCWEstimate += (shaftLength – 45) * 10; // Adjust for length estimatedShaftWeight = targetTCWEstimate – clubHeadWeight – gripWeight; // Clamp shaft weight to realistic ranges if (estimatedShaftWeight 90) estimatedShaftWeight = 90; // For drivers/woods calculatedTotalClubWeight = clubHeadWeight + estimatedShaftWeight + gripWeight; // Rough balance point estimate (inches from butt end) // BP = ShaftLength – (TCW – CHW – GW) / (2 * ScaleFactor) // Simplified: BP decreases as SW increases or shaft gets shorter/head heavier calculatedBalancePoint = shaftLength – 3.0 – (swingWeightTargetNum – 30) * 0.25 – (shaftLength – 45) * 0.1; if (calculatedBalancePoint shaftLength – 5) calculatedBalancePoint = shaftLength – 5; } else { // Empirical estimation for iron/wedge type clubs (shorter shafts) // Estimate target total club weight for irons (e.g., 7-iron at 38″, C8=28) // Base TCW for Iron (38″, C8): ~430g var targetTCWEstimate = clubHeadWeight + gripWeight + 110; // Base guess for shaft + buffer targetTCWEstimate += (swingWeightTargetNum – 28) * 1.5; // Adjust for SW (C8=28) – iron focus targetTCWEstimate += (shaftLength – 38) * 10; // Adjust for length estimatedShaftWeight = targetTCWEstimate – clubHeadWeight – gripWeight; // Clamp shaft weight to realistic ranges for irons/wedges if (estimatedShaftWeight 130) estimatedShaftWeight = 130; calculatedTotalClubWeight = clubHeadWeight + estimatedShaftWeight + gripWeight; // Rough balance point estimate for irons calculatedBalancePoint = shaftLength – 3.0 – (swingWeightTargetNum – 28) * 0.25 – (shaftLength – 38) * 0.1; if (calculatedBalancePoint shaftLength – 4) calculatedBalancePoint = shaftLength – 4; } // Re-calculate the actual achieved swing weight based on the estimated shaft weight // This requires a more complex swing weight formula incorporating the shaft balance point. // A simplified approximation: var finalSwingWeightNum = 0; if (shaftLength > 40) { // Driver/Wood approximation finalSwingWeightNum = 30 + (calculatedTotalClubWeight – clubHeadWeight – gripWeight – estimatedShaftWeight) * 6 + (clubHeadWeight – 200) * 0.5 + (gripWeight – 50) * (-0.5) + (shaftLength – 45) * (-4); // Adjust calculation based on estimated shaft weight and derived TCW finalSwingWeightNum = 30 + (estimatedShaftWeight – 55) * 1.67 + (clubHeadWeight – 200) * 0.5 + (gripWeight – 50) * (-0.5) + (shaftLength – 45) * (-4); } else { // Iron approximation finalSwingWeightNum = 28 + (estimatedShaftWeight – 110) * 1.67 + (clubHeadWeight – 245) * 0.5 + (gripWeight – 55) * (-0.5) + (shaftLength – 38) * (-4); } var finalSwingWeightStr = numberToSwingWeight(finalSwingWeightNum); // Display results document.getElementById("mainResult").textContent = estimatedShaftWeight.toFixed(1) + " g"; document.getElementById("calculatedSwingWeight").textContent = "Achieved Swing Weight: " + finalSwingWeightStr; document.getElementById("totalClubWeight").textContent = "Estimated Total Club Weight: " + calculatedTotalClubWeight.toFixed(1) + " g"; document.getElementById("balancePoint").textContent = "Estimated Balance Point: " + calculatedBalancePoint.toFixed(1) + " in from butt"; document.getElementById("resultsWrapper").style.display = "block"; updateChart(clubHeadWeight, gripWeight, shaftLength, estimatedShaftWeight, calculatedTotalClubWeight); } // Function to update the chart function updateChart(chw, gw, sl, swt, tcw) { var ctx = document.getElementById('shaftWeightChart').getContext('2d'); // Clear previous chart instance if it exists var existingChart = Chart.getChart(ctx); if (existingChart) { existingChart.destroy(); } // Data for the chart: vary shaft weight and see effect on total weight var labels = []; var dataPoints = []; var baseShaftWeight = swt; // Start from the calculated weight var step = 5; // Increase shaft weight by 5g var numPoints = 5; // Show 5 points (calculated weight + 4 variations) for (var i = 0; i < numPoints; i++) { var currentShaftWeight = baseShaftWeight + (i – Math.floor(numPoints/2)) * step; if (currentShaftWeight 130) currentShaftWeight = 130; // Max realistic shaft weight var currentTotalWeight = chw + currentShaftWeight + gw; labels.push(currentShaftWeight.toFixed(0) + "g Shaft"); dataPoints.push(currentTotalWeight); } // Make sure the calculated point is centered or included if (!labels.includes(baseShaftWeight.toFixed(0) + "g Shaft")) { labels.splice(Math.floor(numPoints/2), 0, baseShaftWeight.toFixed(0) + "g Shaft"); dataPoints.splice(Math.floor(numPoints/2), 0, tcw); // Adjust labels/data if we inserted in the middle if (labels.length > numPoints) { labels.pop(); dataPoints.pop(); } } new Chart(ctx, { type: 'line', data: { labels: labels, datasets: [{ label: 'Total Club Weight (g)', data: dataPoints, borderColor: 'rgb(0, 74, 153)', backgroundColor: 'rgba(0, 74, 153, 0.2)', tension: 0.1, fill: true, pointRadius: 5, pointHoverRadius: 8 }] }, options: { responsive: true, maintainAspectRatio: false, scales: { y: { beginAtZero: true, title: { display: true, text: 'Total Club Weight (grams)' } }, x: { title: { display: true, text: 'Estimated Shaft Weight' } } }, plugins: { title: { display: true, text: 'Impact of Shaft Weight on Total Club Weight', font: { size: 16 } }, legend: { position: 'top', } } } }); } // Function to reset calculator inputs to sensible defaults function resetCalculator() { document.getElementById("clubHeadWeight").value = "200"; document.getElementById("gripWeight").value = "50"; document.getElementById("shaftLength").value = "45"; document.getElementById("swingWeightTarget").value = "D1"; // Reset error messages var errors = document.querySelectorAll('.error-message'); for (var i = 0; i < errors.length; i++) { errors[i].textContent = ""; errors[i].classList.remove("visible"); } // Hide results and update chart to default state document.getElementById("resultsWrapper").style.display = "none"; // Re-calculate with defaults to update chart calculateShaftWeight(); } // Function to copy results function copyResults() { var mainResultEl = document.getElementById("mainResult"); var calcSWEl = document.getElementById("calculatedSwingWeight"); var totalCWEl = document.getElementById("totalClubWeight"); var bpEl = document.getElementById("balancePoint"); var formulaExplEl = document.querySelector(".formula-explanation"); var resultsText = "— Shaft Weight Calculation Results —\n\n"; resultsText += mainResultEl.textContent + "\n"; resultsText += calcSWEl.textContent + "\n"; resultsText += totalCWEl.textContent + "\n"; resultsText += bpEl.textContent + "\n\n"; resultsText += "Key Assumptions:\n"; resultsText += "Club Head Weight: " + document.getElementById("clubHeadWeight").value + " g\n"; resultsText += "Grip Weight: " + document.getElementById("gripWeight").value + " g\n"; resultsText += "Shaft Length: " + document.getElementById("shaftLength").value + " in\n"; resultsText += "Target Swing Weight: " + document.getElementById("swingWeightTarget").value + "\n\n"; resultsText += "Formula Context:\n" + formulaExplEl.textContent; // Use the temporary textarea method for copying var textArea = document.createElement("textarea"); textArea.value = resultsText; textArea.style.position = "fixed"; // Avoid scrolling to bottom of page textArea.style.opacity = "0"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'Results copied!' : 'Copy failed!'; // Optionally display a temporary message to the user alert(msg); } catch (err) { alert('Copying results is not supported in this browser.'); } document.body.removeChild(textArea); } // Initial calculation on page load window.onload = function() { // Add Chart.js script dynamically if not present if (typeof Chart === 'undefined') { var script = document.createElement('script'); script.src = 'https://cdn.jsdelivr.net/npm/chart.js'; script.onload = function() { calculateShaftWeight(); // Calculate after chart library is loaded }; script.onerror = function() { alert('Failed to load charting library. Charts will not be available.'); // Still try to calculate if chart fails to load calculateShaftWeight(); }; document.head.appendChild(script); } else { calculateShaftWeight(); // Calculate immediately if Chart.js is already loaded } };

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