Chamfer Calculator
A chamfer callout gives you a leg length and an angle — this turns that into the axial depth you actually program.
What "leg length" and "angle" mean on a print
A callout like "0.020 x 45°" gives the leg length — the width of the flat chamfer surface measured along the part's original face — and the angle that surface makes with the face. The axial depth (how far down you actually plunge or ramp) equals the leg length times the tangent of that angle, and the true length of the chamfered face itself is the leg length divided by the cosine of that angle.
The most common case: 45° chamfers
At exactly 45°, tangent equals 1, so the axial depth simply equals the leg length — the easiest chamfer to picture and check by eye. Any other angle skews that 1:1 relationship, which is exactly why this calculator matters more once you're cutting something other than a standard 45.
Same math on a diameter or a flat edge
Whether the chamfer breaks a flat edge or the end of a turned diameter, the leg-length-and-angle relationship is identical — on a lathe it's simply the depth of an angled facing pass instead of a milled edge break.