Transmission Gear Ratio and RPM Calculator
Use the calculator below to calculate a ring and pinion gear ratio, engine RPM, tire size, or vehicle speed.
Results: Ring & Pinion Gear Ratio
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How to Calculate the Ring & Pinion Gear Ratio
The ring and pinion gear ratio for a differential, also called axle ratio or differential ratio, describes how many times the driveshaft (pinion gear) must rotate to turn the axle shafts and wheels one complete revolution.
This ratio affects vehicle acceleration, towing performance, fuel economy, and engine RPM.
A higher gear ratio provides greater torque multiplication and improved acceleration, while a lower ratio generally reduces engine speed at highway cruising speeds and can improve fuel efficiency.
You can calculate the ring and pinion gear ratio given the number of teeth on the ring and pinion gears using the gear ratio formula.
Gear Ratio Formula
The ring and pinion gear ratio is calculated by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear:
gear ratio = ring gear teeth / pinion gear teeth
So, the gear ratio is equal to the number of ring gear teeth divided by the number of pinion gear teeth.