Gear Tooth Calculator

Inputs

Size system

Specify gear size by metric module or imperial diametral pitch.

Module / DP (m)

Module in mm or diametral pitch in 1/in.

Pressure angle (α)

Standard pressure angle. 20° is the common modern default.

Tooth count (z)

Number of teeth on the gear.

Profile shift (x)

Addendum-modification coefficient. Positive shift increases tooth thickness and can avoid undercut.

Default result

Tooth thickness at pitch(s)

3.142mm

Also computed

Addendum(a)2mm

Dedendum(b)2.5mm

Whole depth(hₜ)4.5mm

Circular pitch(p)6.283mm

Base pitch(p_b)5.904mm

Pitch diameter(d)40mm

Method notes 3 notes

Standard full-depth involute reference: addendum = m, dedendum = 1.25m, whole depth = 2.25m when profile shift x = 0.
Tooth thickness at the pitch circle is s = m·(π/2 + 2x·tan α).
Minimum teeth to avoid undercut at 20° is 18 without profile shift.