Sheet metal
Sheet Metal Bend Calculators
Results are screening estimates and must be verified with your material, tooling, equipment, and a coupon bend before production.
Pick the calculator that matches how your part is dimensioned. Use bend allowance for inside-flange dimensions, bend deduction when the part is dimensioned to outside flanges, and the flat pattern calculator to combine the two for a single-bend blank. The K-factor and reverse K-factor tools cover the neutral-axis assumption that drives both. Default material constants are documented at /reference/data-sources/.
Interactive calculator
Sheet Metal Bend Allowance Calculator
Bend allowance0.1334 in
Neutral axis radius0.0849 in
Static reference
Common thickness, radius, and angle combinations
Swipe table horizontally for more columns.
| Gauge | Thickness | Inside radius | Angle | Bend allowance | Bend deduction |
|---|---|---|---|---|---|
| 20 ga | 0.0359 in / 0.912 mm | 0.0359 in / 0.912 mm | 45 deg | 0.040 in | 0.0194 in |
| 16 ga | 0.0598 in / 1.519 mm | 0.0897 in / 2.278 mm | 90 deg | 0.1804 in | 0.1186 in |
| 14 ga | 0.0747 in / 1.897 mm | 0.0747 in / 1.897 mm | 120 deg | 0.2222 in | 0.2954 in |
| 12 ga | 0.1046 in / 2.657 mm | 0.1569 in / 3.985 mm | 45 deg | 0.1577 in | 0.0589 in |