Calculator cluster

Gears Calculators

Spur-gear ratio, RPM, tooth count, module, pitch diameter, center distance, circular pitch, rack travel, torque, and pitch-line speed calculators.

11 calculators in this cluster

This cluster focuses on basic external spur-gear geometry and ideal ratio relationships. Module, tooth count, pitch diameter, circular pitch, and center distance are tightly linked, so a change to one design choice can be checked quickly against the others.

The geometry tools assume standard spur-gear relationships unless the calculator says otherwise. Detailed gear design still requires checks for pressure angle, profile shift, backlash, tooth strength, contact stress, face width, material, lubrication, accuracy grade, and manufacturing constraints.

A practical calculation workflow

Step 1

Set the ratio

Choose driver and driven tooth counts to establish the ideal speed ratio before calculating shaft speed or torque change.

Open Gear Ratio

Step 2

Resolve the geometry

Use module and tooth count to calculate pitch diameter, then verify the resulting center distance for the gear pair.

Open Gear Pitch Diameter

Step 3

Check operating speed

Use pitch diameter and RPM to estimate pitch-line velocity when screening lubrication and operating conditions.

Open Gear Pitch Line Velocity

All Gears calculators

Choose the variable you know and the quantity you need to solve. Each tool shows its formula, default worked example, and nearby calculations.

Gear Ratio Calculator

Calculate ideal external gear ratio from driver and driven gear tooth counts.

Gear RPM Calculator

Calculate driven gear RPM from driver RPM and the tooth counts of a simple external gear pair.

Gear Teeth Calculator for Target RPM

Estimate the driven gear tooth count required to reach a target RPM from a known driver gear and speed.

Gear Pitch Diameter Calculator

Calculate standard metric spur-gear reference diameter from module and number of teeth.

Gear Module Calculator

Find the metric module that matches a measured or specified spur-gear reference diameter and tooth count.

Gear Center Distance Calculator

Calculate center distance for two standard external spur gears from module and tooth counts.

Gear Circular Pitch Calculator

Calculate circular pitch for a metric gear from module using the standard pi-times-module relationship.

Gear Outside Diameter Calculator

Calculate tip or outside diameter for a standard full-depth external metric spur gear.

Rack Travel per Pinion Revolution Calculator

Calculate rack linear travel per pinion revolution from spur-gear module and pinion tooth count.

Gear Pitch Line Velocity Calculator

Calculate spur-gear pitch-line velocity from reference diameter and rotational speed.

Gear Torque Ratio Calculator

Estimate ideal driven-shaft torque from input torque and driver/driven gear tooth counts.

Practical notes