CraftM8QuiltM8Calculators › Binding

How much binding?

Continuous double-fold binding for any quilt: how many strips to cut and how much fabric to buy — with the join loss most calculators skip. Run it on the finished size, after borders.

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Type it the way you say it — 2 1/2, 2.5 or 6,5 all read the same.

The usual assumptions · usable width of fabric · how joins are counted · corners and tail · flat allowance
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Counting every join is more accurate and buys a little more; the flat allowance is what quilting books print.

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You need
5/8 yd
fabric to buy
8 strips · 20"

Perimeter: 264" · Cut in total, joins included: 295" · Joins: 7 joins · Lost per join: 3" · Lost to joins: 21" · Usable binding after joins: 299"

Cross-grain binding, cut across the width of fabric. For a curved edge you want bias binding instead.
Show the maths
1Perimeter — 2 × (60" + 72")264"
2Lost to joins — 7 joins × (2 1/2" + 1/2")21"
3Binding needed — 264" + 10" (corners) + 21" (joins)295"
4Strips — 295" ÷ 40" = 7 3/8 → round up8
5Fabric used — 8 × 2 1/2"20"
6Fabric to buy — 20" → round up to the next 1/8 yd5/8 yd

Cross-grain binding, cut across the width of fabric. Every join costs a strip width plus two seam allowances, and each extra strip adds a join.

Where the formula comes from

Perimeter plus an allowance for corners and joins; strips from the usable width of fabric, not the printed bolt width; fabric rounded up to the eighth of a yard, the smallest cut most shops sell. The precise model itemises what each diagonal join really costs and solves the resulting fixed point — each added strip introduces another join.

  • Continuous cross-grain binding. Perimeter plus an allowance for mitred corners and the starting tail. The precise model then itemises the join loss — each diagonal join consumes about a strip width plus two 1/4" seam allowances — and solves the resulting fixed point, because each added strip introduces another join.
  • Flat allowance (books). The 10–15" lump allowance printed in most quilting books is a small-quilt approximation that ignores per-join loss; it under-buys by one strip on every case tested (60×72, 120×120, 36×36, 104×116). Retained as an option for pattern-matching.
  • Usable width of fabric. Quilting cotton is sold on 42" bolts; 40" is the planning figure after selvage removal and shrinkage.

This is the app's own arithmetic running in your browser, put through the same worked examples every time this site is built.

A worked example

The worked example is the how-to walkthrough quilt: 60″ × 72″, 2 1/2″ strips, on the book-style flat allowance. The same case is a committed test vector.

1Perimeter — 2 × (60" + 72")264"
2Binding needed — 264" + 12" (corners & joins)276"
3Strips — 276" ÷ 40" = ≈ 6 7/8 → round up7
4Fabric used — 7 × 2 1/2"17 1/2"
5Fabric to buy — 17 1/2" → round up to the next 1/8 yd1/2 yd

Works with

In the app, this answer joins a quilt

Save it to a project, add the other tools' answers, and the shopping list totals every fabric with one rounding — then prints a cut sheet for the table. Offline, no account, one payment, yours forever.

In development A closed test on Google Play is the next step.

Everything the app does →