Fabric math, done for you
Free calculators for quilters and home sewists. Type in your measurements, get the amount to buy and the pieces to cut, and see exactly how the number was worked out.
Quilting calculators
- Quilt backing calculator
Backing size, the best seam layout, and yards or meters to buy.
- Quilt batting calculator
The batting size you need and the smallest packaged batting that fits.
- Quilt binding calculator
Binding length, how many strips to cut, straight grain or bias.
- Quilt border calculator
Strips and yardage for up to three borders, plus the new quilt size.
- Fat quarter calculator
How many fat quarters, charm packs, layer cakes or jelly rolls a quilt needs.
- Half square triangle calculator
Cutting sizes for HSTs made 2, 4 or 8 at a time, with trim sizes.
Curtain and home calculators
- Curtain fabric calculator
Widths, cut drop with pattern repeat, meters to buy, and lining.
- Roman shade fabric calculator
Cut sizes, fabric and lining for a roman shade or blind, plus fold spacing.
- Cushion cover fabric calculator
Cut pieces and yardage for zip or envelope covers, with piping.
- Tablecloth size calculator
The cloth size for any table and drop, and the fabric to sew one.
Guides
- Standard quilt sizes
Bed and quilt dimensions, and how to pick a size that hangs right.
- How to measure for curtains
Width, drop and the small decisions that make curtains fit.
- Curtain fullness and headings
What each heading looks like and the fullness it needs.
- Understanding fabric widths
What widths fabric comes in and how much of it you can actually use.
- Quilting precuts explained
Fat quarters, charm packs, jelly rolls and layer cakes, with sizes.
How SewCalc works
Every calculator on this site shows its working: the formula in plain language, a worked example, and the assumptions behind it. The results are careful estimates based on standard practice, and the final check is always yours, because your fabric, pattern and technique are the real authority. If a tool ever gives you a number that looks off, tell us with the feedback buttons at the bottom of the page and we will look into it.