Quilt batting & finished size calculator
Batting has to be bigger than the quilt top, with spare on every side for loading the frame and squaring up afterwards. Type the finished quilt size (or pick a common preset) and the overage you want, and the calculator gives the piece to buy in inches, plus yards of length if your shop sells batting off a roll. It runs in your browser.
A 50 by 60 inch throw with 6 inches of batting overage on every side needs batting 62 inches wide by 72 inches long, which is 2 yards of length.
- Runs in your browser
Your quilt
Presets are ballparks. Edit width and length to match your pattern.
Usual range 4–8 in. Default 6. Added on every side.
Doesn't change the math. It only adds a reminder to the result.
finished — batting — by the yard — package —
Batting to buy inches
Package sizes: Hobbs standard sizes as listed by retailers, checked October 2026.
A worked example
A 50 × 60 inch throw with 6 inches of batting overage on every side:
- Batting width = 50 + (2 × 6) = 62 inches.
- Batting length = 60 + (2 × 6) = 72 inches.
- By the yard = 72 ÷ 36 = 2 yards of length. You still need a roll or package at least 62 inches wide.
Trimming excess is easy. Piecing batting mid-quilt because you ran short is not.
Common quilt sizes (ballparks)
These are everyday finished-size ranges quilters use when a pattern doesn't name a mattress. Your pattern wins if it disagrees. Mattress depth and drop change bed quilts a lot, so treat the table as a starting point, not a shopping rule.
| Name | About | Notes |
|---|---|---|
| Baby / crib | 36 × 52 | Also used for small lap quilts |
| Throw / lap | 50 × 60 | Sofa and wheelchair throws vary widely |
| Twin | 70 × 90 | Add length for pillow tuck if you want it |
| Full / double | 80 × 90 | Often close to twin length, wider |
| Queen | 90 × 100 | Common longarm reference size |
| King | 110 × 108 | Some patterns use 108 × 108 square |
How the math works
- Batting width = finished width + (2 × overage per side).
- Batting length = finished length + (2 × overage per side).
- Yards of length (if sold by the yard) = batting length ÷ 36, rounded up to the next eighth yard. You still need a roll or package wide enough to cover the batting width.
Batting shrinks too. According to The Warm Company, cotton batting shrinks about 3% on its first wash, and that shrinkage is what gives the crinkled look many quilters like. The overage here is for loading and squaring up, so it won't cover shrinkage if you need the washed quilt to be an exact size.
Fabric for the top, binding and backing still belongs in the yardage calculator and binding calculator.
Questions
How much overage should I leave?
Four to eight inches on each side is the usual range. Four is tight but workable if you're careful loading a longarm; six is a comfortable default; eight gives you room when the top isn't perfectly square or the batting shifts. Trimming excess is easy. Piecing batting halfway through a quilt is not.
Why don't package sizes match my quilt exactly?
Packaged batting comes in standard sizes. The calculator tells you which one covers your quilt, or when you need batting by the yard. A slightly larger package is fine; a smaller one isn't.
Does loft change how much batting I buy?
Not the outside measurements. Loft changes how the quilt feels and how much the edges want to stretch when you quilt. High loft is one more reason not to skimp on overage.
Is this the same as backing yardage?
No. Backing is fabric yardage (see the yardage calculator). Batting is the middle layer, often sold in packages or by the yard from a roll of fixed width. This tool sizes the batting piece, not the fabric.
Can I use centimeters?
The calculator works in inches, because batting packages and quilt patterns are sold and written in inches almost everywhere. Divide centimeters by 2.54 before you type them in.
Updated