StitchTip calculator
Hat project calculator
Estimate hat yarn from the straight section, reduced crown area, folded brim and a measured swatch.
How this tool works
The straight section uses the full finished circumference. The crown decrease section uses half that area to reflect narrowing, and a folded brim adds its second layer separately.
Example calculation
For a 56 cm hat with 22 cm total height and a 7 cm crown, only the lower 15 cm uses the full circumference.
Frequently asked questions
Why enter crown depth?
A decreasing crown uses less fabric than a straight cylinder, so separating it avoids systematic overestimation.
Should circumference include negative ease?
Yes. Enter the finished circumference you intend to make.