Quilt Backing & Batting Calculator

Your measurements and assumptions

Use the actual product label and your measured quantities. Starting values are editable examples, not universal rates or product specifications. Keep the units beside each input.

Method and assumptions

required_width = quilt_width + 2*side_overhang; cut layout determines purchased length

Each join consumes two seam allowances. Full fabric lengths are joined across the required backing width; grain direction follows the selected orientation.

Batting dimensions are shown separately. Choose a batt at least that large and follow the supplier’s joining and shrinkage guidance.

Example with the selected inputs

• Batting length: 200 cm
• Batting width: 160 cm
• Backing fabric lengths: 2
• Length per backing strip: 200 cm
• Required quantity: 4.4 m
• Packs to buy: 9
• Purchase quantity: 4.5 m
• Left over: 0.1 m

Change the inputs to match your own task. Whole packages are rounded up after allowances, so purchase quantity and actual requirement can differ. Apply each allowance once.

Worked example

With Quilt length: 180 cm; Quilt width: 140 cm; Extra on each side: 10 cm; Usable fabric width: 110 cm; Seam allowance per edge: 1 cm; Backing orientation: Lengthwise; Extra allowance: 10 %; Pack size: 0.5 m, the calculator returns Batting length: 200 cm.

Method and assumptions

Each join consumes two seam allowances. Full fabric lengths are joined across the required backing width; grain direction follows the selected orientation. Batting dimensions are shown separately. Choose a batt at least that large and follow the supplier’s joining and shrinkage guidance.

Common-value reference

The reference cases change only Quilt length. The remaining inputs stay at the displayed values. These are worked scenarios, not universal rates, dimensions, product specifications or current shop prices.

Questions and answers

How is this example calculated?

Each join consumes two seam allowances. Full fabric lengths are joined across the required backing width; grain direction follows the selected orientation. Batting dimensions are shown separately. Choose a batt at least that large and follow the supplier’s joining and shrinkage guidance. In the displayed example, Quilt length: 180 cm; Quilt width: 140 cm; Extra on each side: 10 cm; Usable fabric width: 110 cm; Seam allowance per edge: 1 cm; Backing orientation: Lengthwise; Extra allowance: 10 %; Pack size: 0.5 m. The calculated outputs are Batting length: 200 cm; Batting width: 160 cm; Backing fabric lengths: 2; Length per backing strip: 200 cm. Keep the labels and units with these numbers: they describe this particular combination of inputs, not a result that can be reused after the measurements or assumptions change.

What changes when I edit Quilt length?

The table isolates that input while keeping the other displayed settings fixed. For Quilt length: 90 cm, the result is Batting length: 110 cm; for Quilt length: 540 cm, it is Batting length: 560 cm. Those values come from the same calculator used on this page. They show the effect of changing the input, rather than prescribing which input is right for your own task.

How should I use the different result figures?

Read each named quantity separately: Batting length: 200 cm; Batting width: 160 cm; Backing fabric lengths: 2; Length per backing strip: 200 cm. A value with a different label or unit answers a different part of the calculation. Check the measurements and assumptions before using any figure. The reference cases explain the arithmetic under their stated conditions; they do not verify a product label, a recipe or the conditions of a particular project.