RoofTally

RoofTally: free roofing calculators, sources on every figure

Roof area, shingles or tiles, battens and underlayment, from manufacturer coverage figures.

Three calculators for homeowners and small contractors: roof area, squares and bundles of shingles with underlayment, ridge cap, nails and drip edge; the pitch in x:12, degrees and the area multiplier; UK roof tiles per m² with battens and ridge tiles. No account, no address form, nothing stored on our servers.

Roof shingle calculatorRoof tile calculator (UK)

The calculators

How it works

  1. Type each roof section as a rectangle on the plan: length along the ridge, width from eave to eave, the overhang past the walls, the pitch (x:12 or degrees) and whether it is a simple gable or a hip. An L-shaped house is two sections; a garage or a dormer is another.
  2. Pick the product: 3-tab or architectural shingles with the underlayment and ridge cap, or a UK tile type. Every coverage figure starts from the manufacturer data sheet and shows its source and the date it was read under the field; change any of them.
  3. Read the quantities rounded up to what you buy: bundles, rolls, ridge cap bundles, pounds of nails, drip edge pieces, or tiles, metres of batten and ridge tiles, and a cost range from a published cost guide with its year. The sections stay in your browser, so the tile calculator and the Pro list see the same roof.

Units follow the region you pick: US (ft, sq ft, squares, $) or UK / metric (m, m², £). The maths is the same everywhere: roof area = footprint x the pitch multiplier; the units, the currency and the cost presets change.

Where the figures come from

Bundles per square from the Owens Corning specification guide (Owens Corning, Section 07 31 13 specification guide, 2013, TruDefinition Oakridge shingles, read 2026-09-20) and IKO (IKO, "How Many Square Feet in a Bundle of Shingles", 19 July 2023, read 2026-09-20); waste from IKO’s measuring guide; roll coverage from Owens Corning and Atlas; ridge cap from a GAF listing and the IKO data sheet; tiles per m² from the Marley product pages (Marley, Modern interlocking concrete roof tile, technical specification, read 2026-09-20) and the BMI Redland pages; cost ranges from HomeAdvisor (US, 2026) and MyJobQuote (UK, 2026). Each calculator lists its sources with the date they were read, and every figure is yours to change.

Planning quantities from manufacturer coverage figures and published cost ranges, each with its source and date: measure the roof and follow the product data sheet. Not a structural assessment.

Ordering for the whole roof? Pro prints the materials list.

Every section with its area, the totals in bundles or tiles, underlayment, ridge, nails, drip edge, waste and the cost range, printable and as an Excel file.

See Pro

Frequently asked questions

Are the calculators free?
Yes, all three, with no limit, no sign-up and no address to type. Pro is a paid extra for people ordering for a whole roof who want the materials list and the estimate on one printable sheet with an Excel export; the free tools do not change.
How accurate is a roof area from the footprint?
For a roof where every slope has the same pitch, footprint x multiplier is exact, gable or hip. Dormers, different pitches on wings and valleys between sections are what the sections list is for: add each part as its own rectangle with its own pitch. The result is a planning quantity; the roofer measures before ordering.
Do you sell leads or pass my details to roofers?
No. There is no address form and no quote request; the numbers you type stay in your browser. The only thing that leaves your device is the email you type at Stripe if you buy Pro.
What does Pro add?
One sheet for the whole roof: every section with its area, the totals in squares and bundles or tiles and battens, underlayment, ridge, nails, drip edge, waste and the cost range by material with its source and year. Printed or saved as PDF from the browser, or exported to Excel with the sources on their own sheet.