Free roofing calculatorsRoofing math, shown in full.
Free calculators that turn the measurements you can take yourself into the units roofers use: pitch, squares and shingle bundles. No signup, formulas shown.
Pick the number you need.
Every result prints the formula it used, so you can check the working or repeat it by hand.
Roof Replacement Cost Calculator
A low to high cost range from your squares and material, split into materials, labor and tear-off.
Open calculator 02Roof Pitch Calculator
Enter rise and run, or an angle, and get the pitch as X:12, the angle in degrees, the pitch multiplier and the slope percentage.
Open calculator 03Roofing Square Calculator
Enter roof length, width and pitch to get true roof area, roofing squares with waste and the shingle bundles to order.
Open calculator 04Roof Area Calculator
True surface area for gable, hip, shed and flat roofs from the house footprint.
Open calculator 05Metal Roof Cost Calculator
Installed cost for eight metal roof types, from corrugated to copper, with old roof removal and the same roof in asphalt for comparison.
Open calculator 06Squares to Bundles Calculator
Convert squares or square feet to shingle bundles, or work out how much roof your bundles will cover.
Open calculator 07Roofing Nail Calculator
Nails and boxes for your squares and shingle type, based on manufacturer piece counts and the building code.
Open calculator 08Roof Truss Calculator
Top and bottom chord lengths, peak height and how many trusses you need, for common, mono and scissor trusses.
Open calculator 09Roof Sheathing Calculator
Plywood or OSB sheets for your roof, the minimum panel thickness for your rafter spacing, nails and cost.
Open calculator 10Attic Ventilation Calculator
The vent area your attic needs under the IRC 1/150 and 1/300 rules, split into intake and exhaust, and the vents to buy.
Open calculator 11Siding Calculator
Squares, pieces and boxes of siding for your walls and gables, with trim and nails.
Open calculatorWhat a roof costs, with the sources listed.
All roofing cost guides. Cost figures on this site are national estimates, not quotes, researched from public sources.
- Roof Replacement CostThe full job, per square and in total
- Asphalt Shingle Roof CostThree-tab, architectural and premium grades
- Metal Roof CostCorrugated, standing seam and more
- Tile Roof CostConcrete, clay, terracotta and slate
- Roof Repair CostCommon repairs, and when to replace instead
- Flat Roof Replacement CostMembrane systems for low-slope roofs
Before you call a roofer.
Each guide comes with a small tool to check your own roof.
How Long Does a Roof Last?
Lifespan by material.
Tool: roof age checkDoes Homeowners Insurance Cover Roof Replacement?
What a policy pays for.
Tool: claim payout estimatorRoof Warranty Explained
What shingle warranties cover.
Tool: claim checkSigns You Need a New Roof
The warning signs, and how to sort yours.
Tool: checklistHow the numbers are produced.
Plain arithmetic
The calculators are plain arithmetic. Each one prints the formula it used next to every result.
Public sources
Manufacturer product data, retail material pricing, federal wage statistics and published contractor cost surveys.
No claims we can't back
Nobody here installs roofs, and the site does not claim otherwise. The methodology page lists every source.