Gear Center Distance Calculator

Inputs

Known pitch

Choose the pitch value used by both meshing gears.

Pitch value (m)

Module in mm, diametral pitch in 1/in, or circular pitch in mm.

Pinion teeth (z₁)

Number of teeth on the pinion or first gear.

Gear teeth (z₂)

Number of teeth on the mating gear.

Default result

Center distance(a)

60mm

Also computed

Pinion pitch diameter(d₁)40mm

Gear pitch diameter(d₂)80mm

Ratio(i)2

Module(m)2

Diametral pitch(DP)12.7

1/in

Circular pitch(p)6.283mm

Method notes 3 notes

For standard unshifted external spur gears, center distance is half the sum of the pitch diameters.
Module form: a = m·(z1 + z2)/2. Diametral-pitch form: a(in) = (z1 + z2)/(2·DP).
Profile shift, backlash allowance and nonstandard working pressure angle can change the operating center distance.