Quilt maths that is exact, works with no signal, and does not want an account.

Binding length, backing yardage, how many 5″ squares a fat quarter really gives you — answered in the fractions you cut in, with the working shown so you can check it against your own.

Twenty-eight calculators are free. All of them. Not a trial, not a teaser: a calculator that answers one question about one cut of fabric is free in this app and will never move behind a purchase.

What it works out

• Binding — continuous strips, mitred corners, the join loss most calculators skip
• Backing — panels, seam direction, whether wide backing is actually cheaper
• Borders — butted or mitred, with the mitre allowance
• Half-square and quarter-square triangles, flying geese, square-in-a-square
• On-point setting and corner triangles
• Sashing, cornerstones, block layout for a target size, bed sizes with drop
• What a fat quarter, a charm pack or a jelly roll yields for your patch size
• Whether the precut or the yardage is genuinely cheaper, per usable square inch
• Roughly what longarm quilting will cost, and what the quilt will weigh to post
• Whether your quarter-inch seam is actually a quarter inch

Why the numbers are worth trusting

Every formula is written twice — once in the app, once as a separate reference implementation — and the two are checked against 10,897 committed test cases before a release is built. Where a number is an estimate rather than an exact answer, the app says so on the screen where you read it, and lists every one of them in Settings. Where a formula came from is in the app too: 75 sources, one per calculation, readable without paying for anything.

Fabric amounts and cut sizes always round up. A quarter inch too much is a scrap; a quarter inch too little is a ruined cut.

What it will not do

No account. No sign-in. No analytics, no advertising, no crash reporting — nobody is told which tools you open. Everything is worked out on the phone, and nothing you type is sent anywhere. Your projects are a file you can export to plain text whenever you like.

Whatever the app asks Android for is named on the About screen, with the reason, and checked against the built app on every release.

What costs money

Nothing you need to answer a question. The Project Pack (€7.99) keeps every worksheet for one quilt together, sums the fabric into one shopping list with one rounding, and prints a cut sheet. The Business Pack (€4.99) is for quilters who sell — longarm quoting, pricing, time and stash valuation. Both together, €9.99. Once. There is no subscription and there never will be.

Works fully in inches and in centimetres — and metric is not a relabelling: it buys in 1 cm steps and cuts to the millimetre.

Everything is designed for reading at a cutting table: large touch targets, full support for the largest system text size, and a cut sheet that stays awake and stays large while you work through it.

Also known as: quilt mate, quiltmate, quilt m8, craft mate, craftmate — QuiltM8 is part of the CraftM8 family.