Stitchgrid

Label arithmetic · physical gauge span (4 in = 10.16 cm)

Yarn substitution calculator

Divide the original length you need by the length on one substitute ball, then round up. Optional mass and cost totals, gauge comparison normalised to per 10 cm (4 in = 10.16 cm), and warnings when fibre or ply differ. Different fibre or ply are not guaranteed interchangeable.

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How to use this calculator

  1. Enter the required length. Use the original pattern total or a yardage result in metres or yards.
  2. Enter the substitute ball. Type the length on one substitute ball. Optional mass and cost estimate total weight and spend after ceil.
  3. Compare gauge and fibre. Enter stitches and rows over 4 in or 10 cm from each label. Comparison normalises to per 10 cm using 4 in = 10.16 cm. Different fibre or ply is flagged as not guaranteed interchangeable.

Worked example

Example: you need 1000 m. Each substitute ball is 210 m. Balls = ceil(1000 ÷ 210) = 5. Purchased length = 1050 m. If gauges differ after physical span conversion, swatch before committing.

Common questions

How many substitute balls do I need?

Balls needed = ceil(required original length ÷ length on one substitute ball). Only the lengths you enter are used—no stretch or density factor is applied.

What if the gauges differ?

Readings are compared per 10 cm. A 4 in span is 10.16 cm, so stitches and rows scale by 10/10.16. Equal printed numbers across spans are not an exact physical match. The tool does not rewrite stitch counts—swatch before committing.

Are different fibres interchangeable?

Not by default. Matching length—or even gauge—does not guarantee interchangeability when fibre or ply differ. Treat that as a label warning, then swatch.

Where do the numbers come from?

Only from the lengths, gauge and fibre notes you type in this browser tab. Nothing is uploaded for this tool.

Sources and limits

Ball counts are ceil division of your lengths. Gauge comparison uses the physical span 4 in = 10.16 cm (scale × 10/10.16 to per 10 cm). Measured conversion is separate from ball-band charts that sometimes print matching 4 in / 10 cm counts as a label convention. Craft Yarn Council yarn weight system ranges are guidelines only; follow the pattern gauge. Contact hello@imagetocrochetpattern.com.