CraftNumaV0.1

Knitting & crochet

Yarn ball count

Calculate how many whole balls cover a known yarn length, with an optional extra allowance.

Use a single decimal point or comma, without thousands separators or unit symbols. All lengths use the selected unit. Values must be 0–1,000,000; dimensions and swatch counts must exceed zero. Counts must be whole numbers. Extra allowance: 0–100%; lengthwise shrinkage: 0–50%.

Your results

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Assumptions & limits

All balls have the same stated length. The required project length must come from your pattern or a separate estimate; this tool cannot infer it from a garment size. Dye lots, unusable ends and yarn substitution still need checking.

Formula

needed = L × (1 + extra/100); balls = ceil(needed / B); leftover = balls × B − needed

L
Required yarn length
B
Length per ball
extra
Extra allowance (%)

Worked example

L = 1000 m; B = 220 m; extra = 10% → 1100 m; 5; 0 m.

Results show up to 8 decimal places. Small values use scientific notation; calculations use unrounded factors.

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