# Diametral Pitch

on . Posted in Gear Diametral pitch, abbreviated as DP, is the ratio of the number of teeth to the pitch circle diameter.

## Diametral Pitch formula

$$\large{ DP = \frac{n}{PD} }$$
Symbol English Metric
$$\large{ DP }$$ = dimetrical pitch $$\large{dimensionless}$$
$$\large{ PD }$$ = pitch diameter $$\large{in}$$ $$\large{mm}$$
$$\large{ n }$$ = number of teeth $$\large{dimensionless}$$

## Diametral Pitch formula

$$\large{ DP = \frac{\pi}{CP} }$$
Symbol English Metric
$$\large{ DP }$$ = dimetrical pitch $$\large{dimensionless}$$
$$\large{ CP }$$ = circular pitch $$\large{in}$$ $$\large{mm}$$
$$\large{ \pi }$$ = Pi $$\large{3.141 592 653 ...}$$

## Diametral Pitch formula

$$\large{ DP = \frac{n_p \; \left( GR \;+\;1 \right) }{2 \; CD} }$$
Symbol English Metric
$$\large{ DP }$$ = dimetrical pitch $$\large{dimensionless}$$
$$\large{ CD }$$ = center distance $$\large{in}$$ $$\large{mm}$$
$$\large{ GR }$$ = gear ratio $$\large{dimensionless}$$
$$\large{ n_p }$$ = number of teeth on the pinion $$\large{dimensionless}$$ Tags: Gear Equations