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.
- Angle is material bend rotation from flat, not the resulting included angle. K factor must be calibrated for material and process.
Example Calculation
- Inside bend radius: 2 mm
- Sheet thickness: 1 mm
- K factor: 0.4
- Bend angle: 90 °
Inside bend radius = 2 mm; Sheet thickness = 1 mm; K factor = 0.4; Bend angle = 90 °. Primary result: 3.7699111843.
Frequently asked questions
How do I use this calculator?
Enter inside bend radius, sheet thickness, k factor, bend angle. The result updates automatically. Use Reset to restore the example values.
What method does it use?
bend allowance=angle radians ×(inside radius+K ×thickness).. Angle is material bend rotation from flat, not the resulting included angle. K factor must be calibrated for material and process.
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.