Material Bend Allowance Calculator

Calculate the bend allowance (BA) of any material.


Sheet Metal Bend Allowance (BA) Formulas

The bend allowance (BA) is the length of the arc of the neutral line between the tangent points of a bend in any material. This bend allowance formula is used to determine the flat pattern length when a bend is dimensioned from :

1) Center of the radius (or)

2) Tangent point of the radius (or)

3) Outside tangent point of the radius on an acute angle bend.

To calculate the BA, the following formula can be used:

BA = A × π180 × (R + KT)


BA - Bend Allowance

A - bend angle in deg

R - inside bend radius in m

K - constant

T - material thickness in m

π = 3.14159