Flat or Low Slope (1.0x)
Standard Pitch (1.15x)
Steep/Complex (1.35x)
Yes (Add $1.50/sqft)
No (Overlay)
Estimated Project Total:
$0.00
*Note: This is an estimate based on national averages. Actual local labor rates and material fluctuations may vary.
How to Calculate Your Roof Replacement Cost
Replacing a roof is one of the most significant investments a homeowner will make. To accurately estimate your costs, you must consider the "roofing square." In the industry, one square equals 100 square feet of roof surface. Our calculator uses your total square footage to determine the number of squares needed and applies material and labor variables.
Key Factors Influencing Roof Pricing
Material Choice: Asphalt shingles are the most common and affordable, while materials like slate or copper can cost five times as much.
Roof Pitch: Steeper roofs (high pitch) require more safety equipment and labor time, increasing the cost multiplier.
Tear-Off: Removing one or two layers of existing shingles adds labor and disposal fees, typically ranging from $1.00 to $2.00 per square foot.
Flashings and Ventilation: Replacing chimney flashings, ridge vents, and skylights are often billed as additional line items.
Realistic Example Calculation
Suppose you have a 2,000 sq. ft. roof and choose Architectural Shingles ($6.50/sq.ft. installed).
Base Material & Labor: 2,000 x $6.50 = $13,000
Standard Pitch Multiplier: $13,000 x 1.15 = $14,950
Old Roof Removal: 2,000 x $1.50 = $3,000
Total Estimated Cost: $17,950
When Should You Replace Your Roof?
Most asphalt roofs last between 20 to 25 years. Signs that you need an immediate replacement include curling shingle edges, bald spots where granules are missing, cracked shingles, or daylight peeking through the roof boards in your attic. If your roof is over 20 years old, it is wise to start budgeting for a replacement even if no leaks are currently present.
function calculateRoofCost() {
var area = document.getElementById("roofArea").value;
var materialPrice = document.getElementById("materialType").value;
var pitchMultiplier = document.getElementById("roofPitch").value;
var tearOffCost = document.getElementById("tearOff").value;
if (area === "" || area <= 0) {
alert("Please enter a valid roof area.");
return;
}
var baseCost = parseFloat(area) * parseFloat(materialPrice);
var pitchAdjusted = baseCost * parseFloat(pitchMultiplier);
var removalTotal = parseFloat(area) * parseFloat(tearOffCost);
var finalTotal = pitchAdjusted + removalTotal;
document.getElementById("totalCostDisplay").innerHTML = "$" + finalTotal.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
document.getElementById("roofResult").style.display = "block";
// Smooth scroll to result
document.getElementById("roofResult").scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}