Roof Shingle Calculator
Squares, bundles and underlayment for a reroof.
Roofing & Siding
Metal Roof Cost Calculator
A budget estimate for a metal roof, separating the roof area and material quantity from the prices you enter yourself.
Your result
Sample values$14,266
Estimated total
1,342
Roof area, ft²
$7,546
Material cost
$5,366
Labour cost
$1,677
Tear off and disposal
40 × 30 ft at 6:12, 10% waste, at the rates shown.
Where the money goes
| Item | Amount |
|---|---|
| Panels, including waste | $6,646 |
| Trim, fixings and extras | $900 |
| Labour | $5,366 |
| Tear off and disposal | $1,677 |
| Estimated total | $14,266 |
How to use this calculator
Enter the footprint and pitch so the roof area can be worked out, then put in the rates you have actually been quoted. Panels are priced on the area including waste because you buy what you cut from; labour and tear off are priced on the real roof area because that is the surface being worked.
Leave tear off at zero for new construction. On a reroof, ask whether the quote includes disposal — skip hire on a full strip is a real cost and it is often quoted separately.
Formula
Roof area = Footprint × √(1 + (Pitch ÷ 12)²)
Ordered area = Roof area × (1 + Waste)
Material = Ordered area × Panel price + Extras
Labour = Roof area × Labour rate
Total = Material + Labour + Tear off
- Roof area
- the actual sloped surface, larger than the footprint
- Ordered area
- what you buy, including the waste allowance
Every price is user entered. Nothing here is a market rate.
Worked example
A 40 ft by 30 ft footprint at 6:12, 10% waste, $4.50/ft² panels, $4.00/ft² labour, $1.25/ft² tear off, $900 of trim.
- 40 × 30 = 1,200 ft² footprint; slope factor 1.1180
- Roof area: 1,200 × 1.1180 = 1,341.6 ft²
- Ordered: 1,341.6 × 1.10 = 1,475.8 ft²
- Material: 1,475.8 × $4.50 = $6,641 plus $900 trim = $7,541
- Labour: 1,341.6 × $4.00 = $5,366
- Tear off: 1,341.6 × $1.25 = $1,677
About $14,584 in total
Understanding your results
This is a budget figure, not a quote. It tells you whether a contractor’s number is in the right region and where the money is going, which is the useful thing to know before three quotes land with wildly different totals.
What it cannot know: access, roof complexity, deck repairs found after the strip, snow guards, skylight flashings, or your local labour market. Any of those can move a real quote by twenty percent, which is why the rates are yours to enter rather than ours to assume.
Questions
About this calculator
Because you pay for what you cut from, not what ends up on the roof. Panels come in fixed lengths and the offcuts are yours. Labour and tear off are charged on the actual roof surface, which is why the two areas differ in the breakdown.
No, and it is not meant to be. It multiplies your rates by a calculated area. A real quote also carries access, complexity, deck condition, flashing details and the contractor’s overhead. Use this to sanity check a quote, not to replace one.
Whatever your supplier quotes delivered, per square foot. Exposed fastener corrugated is usually the cheapest; standing seam costs considerably more per foot but takes less trim and lasts longer. Ask for the delivered figure rather than working from a list price.
Not always. Metal is light enough that many codes allow it over one existing layer of asphalt, which removes the tear off line entirely. Check locally, and be aware that going over the top hides any deck problems until they get worse.
Keep going
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Pitch, angle and rafter length from rise and run.
Siding Calculator
Squares of siding by wall area and openings.
Roof Truss Calculator
Truss count and spacing across a span.
Estimates, not specifications.
Results are based on the values you enter and on typical material
properties. Densities, coverage rates and product sizes vary between
suppliers, so confirm quantities against your supplier's data before
ordering. Structural work must be signed off by a qualified
professional and meet your local building code.