RPM Calculator

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

Speed

Gear ratio (:1)

Tire diameter

Engine RPM (RPM) 3,225.6

Step-by-step with your numbers:

1. Values used:

2. Speed = 60

3. Gear ratio = 4 :1

4. Tire diameter = 25

5. Engine RPM = 3,225.6RPM

Did we solve your problem today?

Find engine RPM from vehicle speed and gearing.

The math behind it

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

Which gear?

Use the transmission top gear for highway cruising RPM.