Shingle Quantity Calculator
ANA›Life Services Authority›National Calculator Authority›Shingle Quantity Calculator
.calc-container { max-width: 640px; margin: 2rem 0; padding: 1.5rem; background: #fff; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.06); font-family: system-ui, -apple-system, sans-serif; } .calc-container h3 { font-family: Georgia, serif; font-size: 1.15rem; color: #1a1a1a; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-row { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; } .calc-row label { min-width: 160px; font-size: 0.9rem; color: #333; font-weight: 500; } .calc-row input[type="number"], .calc-row select { flex: 1; min-width: 120px; max-width: 200px; padding: 0.5rem 0.6rem; border: 1px solid #ccc; border-radius: 4px; font-size: 0.9rem; font-family: system-ui, sans-serif; color: #1a1a1a; background: #fafaf8; } .calc-row input:focus, .calc-row select:focus { outline: none; border-color: var(--ac, #3d5a80); box-shadow: 0 0 0 2px rgba(26,74,138,0.12); } .calc-row .unit { font-size: 0.82rem; color: #888; min-width: 30px; } .calc-btn { display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1.5rem; background: var(--ac, #3d5a80); color: #fff; border: none; border-radius: 4px; font-size: 0.9rem; font-weight: 600; cursor: pointer; font-family: system-ui, sans-serif; } .calc-btn:hover { opacity: 0.9; } .calc-result { margin-top: 1.25rem; padding: 1rem 1.25rem; background: #f0f6fc; border-left: 3px solid var(--ac, #3d5a80); border-radius: 0 6px 6px 0; display: none; } .calc-result.visible { display: block; } .calc-result-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: #666; margin-bottom: 0.25rem; } .calc-result-value { font-size: 1.6rem; font-weight: 700; color: var(--ac, #3d5a80); } .calc-result-detail { font-size: 0.85rem; color: #555; margin-top: 0.5rem; line-height: 1.5; } .calc-note { margin-top: 1rem; font-size: 0.8rem; color: #888; font-style: italic; } .calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-top: 0.75rem; } .calc-grid-item { padding: 0.6rem 0.8rem; background: #f8f9fa; border-radius: 4px; border: 1px solid #eee; } .calc-grid-item .label { font-size: 0.75rem; color: #888; text-transform: uppercase; letter-spacing: 0.04em; } .calc-grid-item .value { font-size: 1.1rem; font-weight: 600; color: #1a1a1a; } @media (max-width: 720px) { .calc-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; } .calc-row label { min-width: auto; } .calc-row input[type="number"], .calc-row select { max-width: 100%; width: 100%; } .calc-grid { grid-template-columns: 1fr; } } .calc-chart { margin: 1rem 0; text-align: center; } .calc-chart svg { max-width: 100%; height: auto; } .calc-chart-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem 1.2rem; margin-top: 0.6rem; font-size: 0.8rem; color: #555; } .calc-chart-legend span { display: inline-flex; align-items: center; gap: 0.3rem; } .calc-chart-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; font-style: normal; } .calc-related { max-width: 640px; margin: 2rem 0 1rem; padding: 1.25rem 1.5rem; background: #f8f9fa; border: 1px solid #e8e8e8; border-radius: 8px; } .calc-related h3 { font-family: Georgia, serif; font-size: 1rem; color: #1a1a1a; margin: 0 0 0.75rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-related-list { list-style: none; padding: 0; margin: 0 0 0.75rem; display: grid; grid-template-columns: 1fr 1fr; gap: 0.4rem 1.5rem; } .calc-related-list li a { font-size: 0.88rem; color: var(--ac, #3d5a80); text-decoration: none; } .calc-related-list li a:hover { text-decoration: underline; } .calc-browse-all { margin: 0.5rem 0 0; font-size: 0.9rem; font-weight: 600; } .calc-browse-all a { color: var(--ac, #3d5a80); text-decoration: none; } .calc-browse-all a:hover { text-decoration: underline; } @media (max-width: 720px) { .calc-related-list { grid-template-columns: 1fr; } }
Shingle Quantity Calculator
Calculate the number of shingle bundles and squares needed for your roofing project based on roof dimensions and pitch.
Roof Length (ft)
Roof Width / Eave-to-Ridge (ft)
Roof Pitch (rise per 12 in run, e.g. 6 for 6:12)
Number of Roof Slopes / Faces
Waste Factor (%)
Calculate
function shiCalc() { var length = parseFloat(document.getElementById('shi-length').value); var width = parseFloat(document.getElementById('shi-width').value); var pitch = parseFloat(document.getElementById('shi-pitch').value); var slopes = parseInt(document.getElementById('shi-slopes').value); var waste = parseFloat(document.getElementById('shi-waste').value); var resultDiv = document.getElementById('shi-result');
// --- Validation --- if (isNaN(length) || length Please enter a valid roof length greater than 0.'; return; } if (isNaN(width) || width Please enter a valid roof width greater than 0.'; return; } if (isNaN(pitch) || pitch 24) { resultDiv.innerHTML = 'Please enter a valid pitch between 0 and 24.'; return; } if (isNaN(slopes) || slopes Please enter a valid number of slopes (minimum 1).'; return; } if (isNaN(waste) || waste 50) { resultDiv.innerHTML = 'Please enter a waste factor between 0% and 50%.'; return; }
// --- Pitch Multiplier --- // Slope factor = sqrt(1 + (pitch/12)^2) var pitchMultiplier = Math.sqrt(1 + Math.pow(pitch / 12, 2));
// --- Flat (plan) area for all slopes --- var flatArea = length * width * slopes;
// --- Actual sloped area --- var slopedArea = flatArea * pitchMultiplier;
// --- Apply waste factor --- var totalArea = slopedArea * (1 + waste / 100);
// --- Squares and Bundles --- // 1 roofing square = 100 sq ft // Standard shingles: 3 bundles per square var squares = totalArea / 100; var bundles = Math.ceil(squares * 3); var squaresCeil = Math.ceil(squares * 10) / 10;
resultDiv.innerHTML = '### Results ' + '' + 'Flat (Plan) Area' + flatArea.toFixed(2) + ' sq ft' + 'Pitch Multiplier' + pitchMultiplier.toFixed(4) + '' + 'Sloped Area' + slopedArea.toFixed(2) + ' sq ft' + 'Waste Factor' + waste + '%' + 'Total Area (with waste)' + totalArea.toFixed(2) + ' sq ft' + 'Roofing Squares Needed' + squaresCeil.toFixed(1) + ' squares' + 'Bundles Needed' + bundles + ' bundles' + '' + 'Bundle count is rounded up to the nearest whole bundle.
'; }
#### Formula
1. Pitch Multiplier = √(1 + (Pitch ÷ 12)²) 2. Flat Area = Length × Width × Number of Slopes 3. Sloped Area = Flat Area × Pitch Multiplier 4. Total Area = Sloped Area × (1 + Waste% ÷ 100) 5. Squares = Total Area ÷ 100 6. Bundles = ⌈Squares × 3⌉
#### Assumptions & References
- One roofing square covers 100 square feet of roof surface.
- Standard three-tab or architectural shingles require 3 bundles per square (each bundle covers ~33.3 sq ft).
- The pitch multiplier converts horizontal (plan) area to actual sloped surface area using the Pythagorean theorem: √(1 + (rise/run)²).
- A waste factor of 10% is typical for simple gable roofs; use 15–20% for complex roofs with hips, valleys, or dormers.
- Reference: Roofing Contractor Magazine; National Roofing Contractors Association (NRCA) guidelines.
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