Knit a Swatch
Knit or crochet a 4×4" gauge swatch and count stitches and rows per 4 inches.
100% Client-Side · Your Project Data Never Leaves
A yarn yardage calculator determines total yardage and skeins needed for knitting and crochet projects from your gauge swatch measurements. Select garment type, size, and enter your yarn's yards-per-skein to get a shopping list with a built-in safety margin for seaming and gauge variation.
Project Settings
Gauge Swatch
Yarn Info
Extra yardage for swatching, mistakes, and seaming
Yardage Results
Total Yardage—
Skeins Needed—
Total Weight—
Total Meters—
Base Yardage—
Safety Buffer—
How It Works
Set Project Type
Choose from common garments (sweater, hat, scarf) or enter custom dimensions.
Enter Yarn Info
Check your skein label for yards per skein and grams. YarnMath does the rest.
Buy the Right Amount
Get total skeins needed with a safety margin for swatching, seaming, and mistakes.
Why Yarn Yardage Math Matters
Running out of yarn mid-project is every knitter's nightmare — especially if the dye lot is discontinued. Buying too much wastes money on skeins you'll never use. YarnMath combines your gauge swatch measurements with standard garment dimensions to calculate the exact yardage you need. The built-in safety margin covers swatching, seaming, and the inevitable frog-and-redo. Every calculation runs in your browser — your project details never touch a server.
Frequently Asked Questions
How do you calculate yarn yardage for a knitting project?
Start by converting gauge to stitches per square inch: gauge is measured over 4 inches, so 20 stitches × 28 rows is 560 stitches in the whole 4×4-inch swatch, and dividing by 16 gives 35 stitches per square inch. Multiply the project's fabric area by the yarn each square inch consumes, which rises with the square root of stitch density rather than with density itself, then add a 10-15% safety margin for swatching, seaming and gauge variation.
How many skeins do I need for a sweater?
Lion Brand's yardage chart puts an adult sweater in medium-weight yarn at 1,125-1,625 yards. YarnMath's defaults - a 40-inch finished chest, a 25-inch body, 20 stitches and 28 rows per 4 inches - come to 1,488 yards of fabric, or 1,637 yards with the standard 10% margin: 8 skeins of 220 yards. Colorwork, cables and a longer body all push it higher. Buy every skein from the same dye lot, because a lot change mid-garment shows.
What is gauge in knitting and why does it matter?
Gauge is the number of stitches and rows per 4 inches of blocked fabric, measured from a swatch. A pattern fixes the stitch count, so your gauge sets the finished size: 200 stitches meant for 5 stitches per inch give a 40-inch chest, but at 4.5 they give 44.4 inches, so a half-stitch miss moves every measurement by about 10%. Gauge also drives yardage, because a finer gauge packs more stitches into each square inch and each square inch then takes more yarn.