Free tools
Sewing & quilting calculators
15 free calculators that do the fiddly sewing math for you — cutting sizes, block counts, and layouts, in inches or centimetres. No signup, results as you type.
- Free, no signup
- Inches or centimetres
- Worked example on every tool
- SewingFabric Yardage CalculatorEnter your piece size, quantity, and bolt width to see exactly how much fabric to buy, how many pieces fit across, and what it will cost.
- SewingFabric Width ConverterConvert a pattern's yardage from one fabric width to another — 44" to 54" or 60" and back — and see how much you save or need extra.
- SewingCircle Skirt CalculatorTurn your waist measurement and skirt length into the waist and hem cutting radii for a full, three-quarter, half, or quarter circle skirt, plus fabric needed.
- SewingSeam Allowance CalculatorConvert between finished size and cut size for any seam allowance — 1/4", 3/8", 1/2", 5/8", 1", or a scant quarter — in either direction.
- SewingElastic CalculatorWork out how long to cut elastic for a waistband, cuff, or sleeve from your body measurement, elastic type, and how snug you want it.
- SewingGathered Fabric CalculatorFind how wide to cut fabric before gathering it to a finished width, at 1.5x, 2x, 2.5x, 3x, or a custom fullness ratio, seam allowances included.
- SewingButton Spacing CalculatorSpace buttons evenly down a shirt, blouse, or coat opening: enter the length, button count, and edge distances to get each mark from the top.
- SewingBias Tape CalculatorWork out the fabric square to cut for continuous bias tape or binding, plus strip width, strip count, and yield, for single- or double-fold tape.
- SewingDart CalculatorTurn the gap between a body measurement and the garment into dart intake per dart and a recommended length for bust, waist, or shoulder darts.
- SewingZipper Length CalculatorFind the standard zipper length to buy for a dress, skirt, pants, jacket, bag, or pillow opening, the zipper type to use, and whether to shorten it.
- QuiltingHalf-Square Triangle CalculatorEnter your finished half-square triangle size and seam allowance to get the exact square to cut, plus how many squares you need for any number of HSTs.
- QuiltingQuarter-Square Triangle CalculatorFind the square size to cut for quarter-square triangles from the finished size and seam allowance, and how many squares make the QSTs you need.
- QuiltingFlying Geese CalculatorGet flying geese cutting sizes for both the traditional one-at-a-time method and the no-waste four-at-a-time method, for any finished size.
- QuiltingHexagon Quilt CalculatorWork out hexagon template width and height, fabric cut size, and strip width from the hexagon side length and your seam allowance.
- QuiltingQuilt Size CalculatorPlan a quilt layout: how many blocks fit your target size with sashing and borders, the actual finished size, and the sashing pieces to cut.
How every calculator works
Answers as you type
No submit button. Results change the moment a measurement does, and empty or invalid fields say so.
Show the working
Each page has a worked example built from the same math as the calculator, plus the formula behind it.
Never cut short
Lengths round to 1/8 inch or 0.1 cm, and cutting sizes always round up so a piece comes out big enough.