Quilt Batting Calculator
Find the batting dimensions you need for your quilt top — minimum and recommended sizes.
How to Use the Quilt Batting Calculator
- Enter your finished quilt top width and length in inches.
- Select the overhang amount for each side. More overhang makes quilting easier and gives you room to fix mistakes. 6" per side is the most common recommendation.
- Select the batting shrinkage factor based on the fiber content of your chosen batting.
- Click Calculate Batting to see your minimum and recommended batting dimensions, plus which packaged batting sizes will work for your quilt.
Understanding Batting Overhang
- 4" per side — Minimum for machine quilting on a home machine. Leaves little room for shifting.
- 6" per side — Standard recommendation. Gives you comfortable working room when loading the quilt.
- 8" per side — Best for hand quilting or if using a longarm quilting service. Provides maximum flexibility.
Batting Shrinkage Notes
- Cotton batting can shrink 2–5% when washed. Many quilters pre-wash batting to prevent quilt puckering.
- Polyester batting has virtually no shrinkage and is a good choice if you skip pre-washing.
- The recommended batting size already accounts for the shrinkage percentage you selected.
About this Quilt Batting Calculator
Batting size needs to be larger than the quilt top's finished dimensions, since the quilting process (whether hand or machine quilted) can shift and slightly shrink the layers, and the quilt is trimmed to final size only after quilting is complete, not before.
A standard margin for batting and backing
A common standard is adding 4–8 inches beyond the quilt top's finished size on all sides for both batting and backing fabric, giving enough margin to accommodate quilting shift and allow trimming to a clean final edge without running short on any side.