RoofCalcWorks

Roof Calculator & Roofing Estimator

Calculate your roof area, roofing materials and project cost — free, fast and transparent.

What Do You Want to Calculate Next?

I know my roof dimensions

Calculate roof surface area from length, width and pitch.

Calculate Roof Area

I know my roof area

Calculate roofing squares, shingles and materials.

Roofing Materials

I want material quantities

Shingle bundles, underlayment, ridge cap, drip edge and nails.

Estimate Materials

I want to estimate roof cost

Get an estimated project cost range for your roof.

Estimate Roof Cost

Roofing Guides

Step-by-step measurement and calculation instructions — the how-to behind the tools.

How to Measure Roof Pitch

Four methods, from attic to app.

Roof Pitch Chart

Every pitch with angle, slope and multiplier.

How to Calculate Roof Pitch

Formulas, examples and common mistakes.

How to Measure a Roof

From tape measure to order list.

Roof Pitch at a Glance

Common residential roof pitches from 2/12 to 12/12, drawn to scale. Pick one to calculate its angle, slope and area factor:

ROOF PITCH PROFILES TO SCALE – 2/12 TO 12/12 2/12 9.5° 3/12 14.0° 4/12 18.4° 5/12 22.6° MOST COMMON 6/12 26.6° 7/12 30.3° 8/12 33.7° 9/12 36.9° 10/12 39.8° 11/12 42.5° 12/12 45.0° 6/12 is the most common residential pitch · all profiles drawn to scale
Open the Roof Pitch Calculator

The Roofing Workflow — From Tape Measure to Budget

Every roofing estimate follows the same four steps. Start where you are — each calculator passes its result to the next tool automatically.

  1. 1. Measure Your Roof

    Get the pitch (rise over run) and slope angle of your roof.

    Roof Pitch →Roof Slope →

  2. 2. Calculate Area & Squares

    Turn footprint dimensions into surface area and roofing squares.

    Roof Area →Roof Sq Ft →Roofing Squares →

  3. 3. Estimate Materials

    Shingles, underlayment and every accessory, with waste factored in.

    Shingles →Full Material List →Bundles from Squares →

  4. 4. Estimate Project Cost

    Convert your material quantities into a realistic cost range.

    Roof Cost →Replacement Cost →
19 free calculators — no signup
Every formula openly documented
Inputs never leave your browser

Curious how the numbers are produced? Every formula, assumption and data source is published on the Methodology page.

Roof Calculators

Roof Calculator

All-in-one roof calculator: enter your roof dimensions to calculate roof area, roofing squares, materials and estimated cost.

Roofing Calculator

Free roofing calculator: calculate roof surface area, roofing squares, shingle bundles and underlayment from your roof dimensions.

Roof Area Calculator

Calculate your roof surface area from footprint length, width and roof pitch. Free online roof area calculator with pitch multiplier.

Roof Square Footage Calculator

Estimate total roof square footage from your house length, width and roof pitch. Free roof sq ft calculator.

Roof Pitch Calculator

Calculate roof pitch, slope, angle and pitch multiplier from rise and run. Free online roof pitch calculator with pitch chart.

Roof Slope Calculator

Calculate roof slope ratio, slope percentage, angle and pitch from rise and run. Free online roof slope calculator.

Materials & Squares

Roofing Squares Calculator

Convert roof square feet to roofing squares, with waste adjustment. One roofing square = 100 square feet. Free calculator.

Shingle Calculator

Calculate how many bundles of shingles you need from roof area, pitch and waste factor. Coverage per bundle is fully adjustable.

Roofing Material Calculator

Estimate all roofing materials: shingles, underlayment, starter strip, ridge cap, drip edge and roofing nails from your roof dimensions.

Shingle Bundle Calculator

Convert roofing squares or square feet into shingle bundles. Adjustable coverage per bundle, waste factor and instant bundle count.

Roofing Underlayment Calculator

Calculate underlayment rolls for felt 15#, felt 30# or synthetic underlayment from your roof area, with waste factor and roll coverage.

Roof Sheathing Calculator

Calculate roof sheathing sheets (plywood or OSB) from your roof area. Covers 4x8 sheets, waste factor and sheathing nail counts.

Roof Waste Calculator

Find the right roof waste factor for your roof type and pitch, then see the waste-adjusted squares and bundles you should order.

Ridge Cap Calculator

Calculate ridge cap bundles from ridge and hip lengths, using specialty ridge cap coverage or three-tab shingles cut on site.

Drip Edge Calculator

Calculate how much drip edge you need: roof perimeter plus corner overlaps, in linear feet and 10-foot pieces, with waste factor.

Starter Strip Calculator

Calculate starter strip rolls from your eave length, using self-adhered starter rolls or three-tab shingles cut into starter pieces.

Roofing Nails Calculator

Calculate roofing nails from squares and ridge length. Choose 4-nail or 6-nail patterns and get coil boxes to order.

Metal Roof Calculator

Calculate metal roofing panels, screws or clips and ridge cap pieces for standing seam, 5V crimp, R-panel or corrugated roofs, with waste.

Cost Estimators

Roof Cost Calculator

Estimate your roofing project cost range: materials, labor, tear-off and disposal. Asphalt shingles and metal roofing supported.

Roof Replacement Cost Calculator

How much does it cost to replace a roof? Get an estimated replacement cost range including material, labor, tear-off and disposal.

Metal Roof Cost Calculator

Estimate metal roof cost: standing seam, 5V crimp, R-panel or corrugated, with labor, tear-off and disposal shown as a planning range.