Measure twice, make once
Blocking change projection
Project finished dimensions from the measured change in your blocked swatch.
Start with the calculator. Formula, assumptions, and limits are available when you need them.
Before you use this tool
Measure the same marked sample before finishing and again when completely dry and rested. Keep width paired with width and height with height.
The result predicts comparable fabric behavior; it is not an instruction to stretch a project to those dimensions.
Method and limits
Formula and assumptions
Width and height use their own measured after-to-before ratios. This is a projection from your swatch, not a safe stretching target.
Worked example
Example: a swatch changing from 10 × 10 cm to 11 × 9 cm projects a 50 × 60 cm piece to about 55 × 54 cm.
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.