Tire Size Calculator
Tire diameter & revs.
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Gear Ratio Calculator
Enter driven and drive gear teeth to get the gear ratio.
Gear ratio
—
Driven ÷ drive.
| As a fraction | — |
|---|---|
| Ring teeth | — |
| Pinion teeth | — |
| Type | — |
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Enter your figures above to see the step-by-step working.
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How the Gear Ratio Calculator Works
A gear ratio is the number of teeth on the driven (output) gear divided by the teeth on the drive (input) gear. A differential with a 41-tooth ring gear and an 11-tooth pinion has a 3.73:1 ratio — the driveshaft turns 3.73 times for each turn of the wheels, trading top speed for torque.
Ratios above 1:1 are reductions that multiply torque (good for acceleration and towing); ratios below 1:1 are overdrives that favour top speed and fuel economy. Enter the two tooth counts to get the ratio.
gear ratio = driven (ring) teeth ÷ drive (pinion) teeth
Frequently Asked Questions
How do you calculate a gear ratio?
Divide the number of teeth on the driven gear by the teeth on the drive gear. 41 ÷ 11 = 3.73:1.
What does a 3.73 gear ratio mean?
The input turns 3.73 times for every one turn of the output — more torque and acceleration, at the cost of higher engine RPM at speed.
Higher or lower gear ratio for towing?
Higher (numerically larger, like 4.10) multiplies torque more, which helps towing and acceleration but raises cruising RPM.
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