Sheet-metal calculators
Free bend calculators that run in your browser, using the same formulas as the Coobic editor. Every page shows the formula it uses and a worked example, so you can check the result by hand.
Bend allowance calculator
The arc length the neutral axis travels through a bend — the material the bend consumes. Add it to the flange lengths measured to the bend line to get the flat length.
Bend deduction calculator
What to subtract from the sum of the outside flange dimensions to get the flat blank length. The number most shop drawings are dimensioned around.
K-factor calculator
Work the K-factor backwards from a test bend you have measured, so every later calculation matches your own press brake and tooling.
Sheet metal gauge chart
Gauge number to thickness in millimetres and inches for steel, stainless and aluminium — they are three different scales.
Skip the arithmetic entirely
These calculators handle one bend at a time. The editor applies the same maths to a whole part: draw the flat pattern, add bend lines, and it unfolds and refolds continuously — including dimensioning the folded result and back-solving the flat blank for you.