Quilt Batting Calculator
Batting needs to overhang the top on every side. Enter your quilt dimensions and preferred margin to get the batting size, the smallest standard package that covers it, and how much to buy if you cut from a roll.
Three to four inches is standard; longarm quilters often prefer four or more.
Formula & how it works
Batting size is quilt + overhang × 2 in both directions. The package suggestion picks the smallest common size whose dimensions cover that, allowing for the batting to be turned.
Off a roll, the length needed is whichever batting dimension does not fit within the roll width, converted with ÷ 36 for yards.
Worked example
A 60 × 80 inch quilt with 4 inches of overhang needs batting of 68 × 88 inches — about 41.6 square feet. A standard twin package at 72 × 90 covers it. From a 108-inch roll you would buy 68 inches, roughly 1.9 yards, with the 88-inch dimension running across the roll width.
Choosing and sizing batting
Why the margin exists
Quilting draws the three layers together and the sandwich creeps as it moves through the machine, so a top laid on exactly-sized batting will end up short somewhere. The overhang absorbs that movement and gives something to hold onto while basting.
Packages versus the roll
Packaged batting is easy when your quilt matches a bed size, but odd dimensions leave big offcuts. Buying from a wide roll is generally cheaper per square inch and lets you cut exactly what a quilt needs, with leftovers going to placemats or table runners rather than the bin.
Check the quilting distance
Every batting has a maximum recommended distance between lines of stitching — sometimes as tight as 2 inches, sometimes 8 or 10. Exceeding it lets the batting shift or bunch after washing. Match the batting to how densely you actually intend to quilt.