No (Install over existing)
Yes (Single Layer)
Yes (Double Layer)
Estimated Replacement Cost
Effective Surface Area:0 sq ft
Material & Labor (per sq ft):$0.00
Removal/Tear-off Cost:$0.00
10% Waste Factor:$0.00
$0.00
*Disclaimer: This is a rough estimate. Local labor rates, permit fees, and specific structural repairs are not included.
How to Estimate Your Roofing Costs
A new roof is one of the most significant investments a homeowner will make. Understanding how professional contractors calculate their bids can help you budget effectively and avoid surprises during the renovation process.
Key Factors Influencing Roof Pricing
Square Footage: Roofing is usually calculated in "squares." One square equals 100 square feet. A 2,000 sq. ft. home often has a roof area closer to 2,400 sq. ft. due to overhangs and pitch.
Roof Pitch: The steeper the roof, the higher the labor cost. Steep roofs require specialized safety equipment and more time for workers to navigate.
Material Choice: Asphalt shingles are the most common and affordable (averaging $4-$7 per sq. ft. installed), while luxury materials like slate or metal can exceed $20 per sq. ft.
Tear-Off: Removing old layers of shingles adds labor and disposal fees. If your home has multiple layers of old roofing, the cost increases significantly.
Example Calculation
If you have a 1,500 sq. ft. roof with a standard pitch and choose architectural shingles:
Base Area: 1,500 sq ft.
Pitch Adjustment (Standard): 1,500 x 1.25 = 1,875 sq ft effective area.
Material/Labor ($7.00): 1,875 x $7.00 = $13,125.
Waste Factor (10%): Add $1,312.50.
Total Estimated: Approximately $14,437.50.
function calculateRoofingCost() {
var area = parseFloat(document.getElementById("roofArea").value);
var pitch = parseFloat(document.getElementById("roofPitch").value);
var materialRate = parseFloat(document.getElementById("materialType").value);
var tearOffRate = parseFloat(document.getElementById("tearOff").value);
if (isNaN(area) || area <= 0) {
alert("Please enter a valid roof area.");
return;
}
// 1. Calculate effective area based on pitch
var effectiveArea = area * pitch;
// 2. Base cost (Material + Labor)
var baseCost = effectiveArea * materialRate;
// 3. Removal cost
var removalCost = effectiveArea * tearOffRate;
// 4. Subtotal before waste
var subtotal = baseCost + removalCost;
// 5. Waste factor (10% standard)
var wasteFactor = subtotal * 0.10;
// 6. Grand Total
var totalCost = subtotal + wasteFactor;
// Displaying Results
document.getElementById("effectiveAreaDisplay").innerText = Math.round(effectiveArea).toLocaleString() + " sq ft";
document.getElementById("rateDisplay").innerText = "$" + materialRate.toFixed(2);
document.getElementById("tearOffDisplay").innerText = "$" + removalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("wasteDisplay").innerText = "$" + wasteFactor.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("totalDisplay").innerText = "Total: $" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("roofResult").style.display = "block";
// Smooth scroll to result
document.getElementById("roofResult").scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}