Engineering tool · V0.2

Draft Angle Calculator

Convert feature depth and draft angle into one-side offset and total dimensional change. Useful for early injection-molding geometry checks.

For a two-sided feature such as a width or diameter.
One-side offset
Total dimensional change
Large-end dimension
Angle in radians
offset = depth × tan(angle)

This tool calculates geometry only. It does not determine whether a chosen draft angle is sufficient for a particular resin, texture, tool construction or ejection condition.

How to interpret the result

A 1.5° draft over a 40 mm pull creates about 1.05 mm of offset on each drafted side. If both sides are drafted, the total width change is about 2.10 mm.

Draft recommendations depend on material, surface finish, texture depth, geometry and tooling strategy. Use the calculator to understand the dimensional consequence of a draft decision, then validate the actual draft requirement with the project’s manufacturing context.

Read the draft-angle design guide →