Measure twice, make once
Swatch-based yarn estimator
Estimate yarn for a uniform flat piece from the area and weight of your own washed swatch.
Start with the calculator. Formula, assumptions, and limits are available when you need them.
Before you use this tool
Weigh a dry finished sample without needles, pins or attached extra yarn. Measure only the area represented by that mass.
Target width × height describes a rectangle in the same stitch pattern; sleeves, seams, borders and other structures need separate samples or component estimates.
Method and limits
Formula and assumptions
The target area is divided by the swatch area, then multiplied by swatch weight and allowance. Label length and weight convert that estimate to yarn length and whole balls. A visible ±15% planning band shows sensitivity, not a statistical guarantee. Use only for similarly constructed rectangular fabric with matching stitch pattern, gauge, and density.
Worked example
Example: a 10 × 10 cm swatch weighing 5 g projects 165 g and 330 m for a 50 × 60 cm rectangle with 10% allowance, using 100 m per 50 g ball.
Limits and rounding
Results are planning estimates from the values entered. Displayed decimals are rounded for craft use; whole materials and repeats round up where the method says so. Confirm gauge, material behavior, construction, and finished measurements before committing supplies.