Measure twice, make once
Yarn substitution planner
Turn required yarn length into whole substitute balls, total length, and weight.
Start with the calculator. Formula, assumptions, and limits are available when you need them.
Before you use this tool
Use the original total length, or original ball count × length per ball, then enter the replacement label length. Equal ball weights do not imply equal lengths.
Read quantity and suitability separately: enough yarn may still give the wrong fabric. Confirm washed gauge, drape and care before committing.
Method and limits
Formula and assumptions
Required length plus allowance is divided by substitute length per ball and rounded up. Risk also reflects fiber, yarn structure, blocked gauge, weight category, care, and drape; unknown or different properties require a swatch before purchasing.
Worked example
Example: 850 m plus 10%, using 175 m and 50 g balls, requires 6 balls: 1,050 m and 300 g purchased.
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.