Free Gear Ratio Calculator
Calculate final drive and gear ratios.
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About the Gear Ratio Calculator
Free gear ratio calculator. Work out a gear ratio from the number of teeth, or find the effective final drive ratio — handy for diffs, transmissions and builds.
How it works
- 1
Enter teeth counts
Drive and driven gear teeth.
- 2
Get the ratio
See the ratio instantly.
Frequently asked questions
Divide the driven gear's teeth by the drive gear's teeth — e.g. 41/10 = 4.10:1.
The overall reduction from the engine to the wheels, combining transmission and differential ratios.