---
title: "Backing and Binding Calculator"
date: 2026-05-22
author: "Quiltweb"
featured_image: "https://quiltweb.com/wp-content/uploads/2026/06/green-calculator1.webp"
---

# Backing and Binding Calculator

## Backing & Binding Calculator

Enter your finished quilt top dimensions below to calculate how much fabric you need. It will automagically appear in the boxes at the bottom of the page.

Quilt top size

 Width (inches)  

 Length (inches)  

 

 

Backing options

 Fabric width  44″ fabric / 40″ usable 108″ fabric / 106″ usable 60″ fabric / 58″ usable  

 Extra margin per side  4″ per side (longarm) 3″ per side 2″ per side (home machine)  

 

 

Binding options

 Binding strip width  2½” (standard double-fold) 2¼” 2″ 3″ (wide or flanged)  

 Binding fabric WOF  40″ usable 44″ 42″  

 

 

Backing fabric needed

—

yards

Backing size needed—

Number of panels—

Cut each panel—

 

⚠ Quilt width exceeds fabric width. Check your fabric selection.

 

Binding fabric needed

—

yards

Quilt perimeter—

Total strip length—

Strips to cut—

Strip width—

 

 

 

 **Note:** All yardage is rounded up to the nearest ⅛ yard. Backing uses 40″ usable width for standard 44″ WOF fabric (after removing selvages and allowing for shrinkage). Binding includes 12″ extra for diagonal joins and finishing. Always buy a little extra — fabric is never sorry to be left over!



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Here is a method of creating a backing with the seam on the diagonal, invented by John Flynn. This diagonal backing method works best when the backing size needed is no more than about 1½ times the usable width of your fabric. In Step One, you cut a diagonal line through the length of fabric amount given by the calculator. Slide one side down until you get the width of the quilt top plus 8-1/2″ for the longarmer and a seam allowance. Sew along the diagonal. Trim as shown.

![Step one shows a rectangle labeled Length and Width of Fabric with a diagonal dashed line. Step two, using the Backing and Binding Calculator, displays the rectangle cut along the diagonal with a rotary cutter, and Trim here labels by the cut edges.](https://quiltweb.com/wp-content/uploads/2026/06/Diagonal-Seam-Backing-Cutting-768x610.webp)

### Diagonal Backing Calculator

 Enter the size of your quilt top. This calculator automatically adds 4″ to each side for longarm quilting.

    Quilt Top Width    Quilt Top Length    Usable Backing Fabric Width    Calculate   Calculate Backing     **Enter your quilt top size, then click Calculate Backing.**