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Roof Pitch and Shingle Material Calculator

ANALife Services AuthorityNational Calculator Authority›Roof Pitch and Shingle Material 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; } }

Roof Pitch and Shingle Material Calculator

Calculate your roof's pitch, slope angle, and estimate the number of shingles (squares) needed for your roofing project.

Horizontal Run (ft) — half the building width for a gable roof

Vertical Rise (in) — rise per 12 inches of run

Ridge Length / Building Length (ft)

Waste Factor (%)

Number of Roof Sides

2 (Gable / Hip) 1 (Shed / Lean-to)

Calculate

function rooCalc() { var run = parseFloat(document.getElementById('roo-run').value); var rise = parseFloat(document.getElementById('roo-rise').value); var length = parseFloat(document.getElementById('roo-length').value); var waste = parseFloat(document.getElementById('roo-waste').value); var sides = parseInt(document.getElementById('roo-sides').value); var res = document.getElementById('roo-result');

// --- Validation --- if (isNaN(run) || run Please enter a valid Horizontal Run greater than 0.'; return; } if (isNaN(rise) || rise Please enter a valid Vertical Rise (0 or greater).'; return; } if (isNaN(length) || length Please enter a valid Ridge Length greater than 0.'; return; } if (isNaN(waste) || waste 50) { res.innerHTML = 'Waste Factor must be between 0% and 50%.'; return; }

// --- Pitch --- // Pitch expressed as rise:12 (rise per 12 inches of run) var pitchRatio = rise; // already in rise-per-12 form from user input

// --- Slope Factor (multiplier to convert horizontal area to sloped area) --- // slope_factor = sqrt((rise/12)^2 + 1) var slopeFactor = Math.sqrt(Math.pow(rise / 12, 2) + 1);

// --- Slope Angle --- // angle = atan(rise / 12) in degrees var angleRad = Math.atan(rise / 12); var angleDeg = angleRad * (180 / Math.PI);

// --- Rafter Length --- // rafter_length = run * slope_factor (ft) var rafterLength = run * slopeFactor;

// --- Roof Surface Area --- // One side area = rafter_length * ridge_length // Total area = sides * rafter_length * ridge_length var oneSideArea = rafterLength * length; var totalArea = sides * oneSideArea;

// --- Shingle Squares --- // 1 square = 100 sq ft of roof surface // squares_needed = totalArea * (1 + waste/100) / 100 var squaresRaw = totalArea / 100; var squaresWithWaste = squaresRaw * (1 + waste / 100);

// --- Bundles --- // Standard: 3 bundles per square (for 3-tab shingles) var bundlesNeeded = Math.ceil(squaresWithWaste * 3);

// --- Pitch Category --- var pitchCategory = ''; if (rise ' + 'Roof Pitch' + rise.toFixed(1) + ':12' + 'Slope Angle' + angleDeg.toFixed(2) + '°' + 'Slope Factor' + slopeFactor.toFixed(4) + '' + 'Rafter Length' + rafterLength.toFixed(2) + ' ft' + 'Total Roof Surface Area' + totalArea.toFixed(2) + ' sq ft' + 'Squares (no waste)' + squaresRaw.toFixed(2) + ' squares' + 'Squares (with ' + waste + '% waste)' + squaresWithWaste.toFixed(2) + ' squares' + 'Bundles of Shingles Needed' + bundlesNeeded + ' bundles' + 'Pitch Category' + pitchCategory + '' + ''; }

#### Formulas Used

Slope Factor = √((rise/12)² + 1)

Slope Angle = arctan(rise / 12) × (180 / π)

Rafter Length = Horizontal Run × Slope Factor

Total Roof Area = Number of Sides × Rafter Length × Ridge Length

Squares Needed = Total Roof Area / 100 × (1 + Waste% / 100)

Bundles Needed = ⌈Squares Needed × 3⌉  (3 bundles per square for standard 3-tab shingles)

#### Assumptions & References

More Calculators

References