Garage Door Opening Size Calculator
ANA›Life Services Authority›National Calculator Authority›Garage Door Opening Size 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; } }
Garage Door Opening Size Calculator
Calculate the recommended rough opening size for a garage door based on your vehicle dimensions and required clearances.
Vehicle Width (inches)
Typical car: 70–80 in, SUV/truck: 78–96 in
Vehicle Height (inches)
Typical car: 55–65 in, SUV/truck: 65–80 in
Number of Cars
1 Car 2 Cars 3 Cars
Side Clearance Per Side (inches)
Minimum recommended: 3 in per side
Top Clearance (inches)
Minimum recommended: 2 in above vehicle
Between-Car Clearance (inches, multi-car only)
Space between vehicles in multi-car openings
Calculate
function garCalc() { var vw = parseFloat(document.getElementById('gar-vehicle-width').value); var vh = parseFloat(document.getElementById('gar-vehicle-height').value); var nc = parseInt(document.getElementById('gar-num-cars').value); var sc = parseFloat(document.getElementById('gar-side-clearance').value); var tc = parseFloat(document.getElementById('gar-top-clearance').value); var bc = parseFloat(document.getElementById('gar-between-clearance').value); var resultDiv = document.getElementById('gar-result');
if (isNaN(vw) || vw 120) { resultDiv.style.display='block'; resultDiv.className='calc-result calc-error'; resultDiv.innerHTML='Error: Vehicle width seems too large. Please check your input.'; return; } if (vh > 120) { resultDiv.style.display='block'; resultDiv.className='calc-result calc-error'; resultDiv.innerHTML='Error: Vehicle height seems too large. Please check your input.'; return; }
// Width formula: (vehicle width × number of cars) + (2 × side clearance) + ((num_cars - 1) × between-car clearance) var rawWidth = (vw * nc) + (2 * sc) + ((nc - 1) * bc); // Height formula: vehicle height + top clearance var rawHeight = vh + tc;
// Round up to nearest standard door size (widths: 8,9,10,12,14,16,18,20 ft; heights: 7,8 ft) var standardWidthsFt = [8, 9, 10, 12, 14, 16, 18, 20]; var standardHeightsFt = [7, 8];
var rawWidthFt = rawWidth / 12; var rawHeightFt = rawHeight / 12;
var recWidthFt = null; for (var i = 0; i = rawWidthFt) { recWidthFt = standardWidthsFt[i]; break; } } if (recWidthFt === null) recWidthFt = Math.ceil(rawWidthFt);
var recHeightFt = null; for (var j = 0; j = rawHeightFt) { recHeightFt = standardHeightsFt[j]; break; } } if (recHeightFt === null) recHeightFt = Math.ceil(rawHeightFt);
// Rough opening is door size + 3 inches each side width, + 1.5 inches height (framing allowance) var roughOpeningWidth = (recWidthFt * 12) + 3; var roughOpeningHeight = (recHeightFt * 12) + 1.5;
var widthFtIn = Math.floor(rawWidth / 12) + ' ft ' + (rawWidth % 12).toFixed(1) + ' in'; var heightFtIn = Math.floor(rawHeight / 12) + ' ft ' + (rawHeight % 12).toFixed(1) + ' in';
resultDiv.style.display = 'block'; resultDiv.className = 'calc-result calc-success'; resultDiv.innerHTML = 'Results' + '' + 'Minimum Required Width' + rawWidth.toFixed(1) + ' in (' + widthFtIn + ')' + 'Minimum Required Height' + rawHeight.toFixed(1) + ' in (' + heightFtIn + ')' + 'Recommended Door Width' + recWidthFt + ' ft (' + (recWidthFt * 12) + ' in)' + 'Recommended Door Height' + recHeightFt + ' ft (' + (recHeightFt * 12) + ' in)' + 'Rough Opening Width' + roughOpeningWidth.toFixed(1) + ' in (' + (recWidthFt) + ' ft door + 3 in framing)' + 'Rough Opening Height' + roughOpeningHeight.toFixed(1) + ' in (' + (recHeightFt) + ' ft door + 1.5 in framing)' + ''; }
#### Formulas Used
Minimum Opening Width (in): (Vehicle Width × Number of Cars) + (2 × Side Clearance) + ((Number of Cars − 1) × Between-Car Clearance)
Minimum Opening Height (in): Vehicle Height + Top Clearance
Recommended Door Size: Round up to the nearest standard door width (8, 9, 10, 12, 14, 16, 18, 20 ft) and height (7 or 8 ft).
Rough Opening: Door Width + 3 in (framing) × Door Height + 1.5 in (framing)
#### Assumptions & References
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