Driveshaft RPM Calculator

Inputs

Road speed (v)

Vehicle road speed.

km/h

Tire diameter (D)

Loaded or calculated tire diameter.

Final drive ratio

Axle or differential ratio between driveshaft and wheel.

Additional reduction ratio

Use 1 if the shaft speed you want is directly ahead of the axle. Include transfer or drop-box reduction only when it is between the shaft and wheels.

Critical speed limit

Estimated or manufacturer shaft speed limit for utilization comparison.

rpm

Default result

Driveshaft RPM

3,134rpm

Driveshaft RPM = wheel RPM * final drive * additional reduction.

Also computed

Wheel RPM840rpm

Speed at critical RPM200.2km/h

Critical-speed utilization52.2%

Speed per 1000 shaft RPM33.37km/h

Tire circumference2,075mm

Shaft-to-wheel ratio3.73

Method notes 3 notes

Wheel RPM = road speed / tire circumference. Shaft RPM multiplies wheel RPM by the ratio between the shaft and the wheels.
For a conventional rear driveshaft ahead of the differential, use final drive ratio and leave additional reduction at 1.
This does not check driveshaft tube critical speed, joint angle, balance, torque, plunge, yoke strength or vibration. Use it with a separate critical-speed screen.