Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Full circle only. Waist seam allowance, waistband, stretch, shrinkage and split-panel seam allowances are excluded.
Example Calculation
- Finished waist circumference: 70 cm
- Skirt length: 60 cm
- Radial hem allowance: 2 cm
A 70 cm waist has radius about 11.14 cm; length 60 and hem 2 give outer radius 73.14 cm.
Frequently asked questions
How do I use this calculator?
Enter finished waist circumference, skirt length, radial hem allowance. The result updates automatically. Use Reset to restore the example values.
What method does it use?
waist radius=waist/(2π); outer radius=waist radius+length+hem.. Full circle only. Waist seam allowance, waistband, stretch, shrinkage and split-panel seam allowances are excluded.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.