Sewing calculator
Seam and Hem Allowance Calculator
Turn finished dimensions into cut dimensions with independent edge allowances.
Your measurements
Seam and hem result
- Cut width
- 43.00 in
- Cut height
- 43.00 in
Formula
Cut width equals finished width plus left and right allowances; cut height adds top and bottom allowances.
Assumptions
- Allowances are measured perpendicular to each edge.
- Each edge entry represents the complete allowance required by that edge treatment.
When a tested commercial pattern gives different cutting dimensions or layout instructions, follow that pattern.
Worked example
- 40 × 38 in finished rectangle
- 1.5 in left and right · 1 in top · 4 in bottom
The independent edge allowances produce a 43 × 43 inch cut rectangle.
Verification note
Confirm whether the source measurement is a finished line or an existing cut line before adding anything.