Everyday life

RPM Calculator

Find engine RPM from speed, gear ratio and tire size.

Speed

Gear ratio (:1)

Tire diameter

Calculated Output

Engine RPM (RPM) 3,225.6

Step-by-Step Breakdown

1. Values used:

2. Speed = 60

3. Gear ratio = 4 :1

4. Tire diameter = 25

5. Engine RPM = 3,225.6RPM

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The math behind it

RPM = mph × gear ratio × 336 ÷ tire diameter (in).

Which gear?

Use the transmission top gear for highway cruising RPM.