# Revolutions per Minute from Miles per Hour Calculate the revolutions per minute from a given speed in miles per hour.

##### Sample Calculation
speed = 148 miles per hour
diameter = 34.6 inches
convert the speed of miles per hour to inches per minute
there are 63360 inches in one mile and 60 minutes in an hour
148 miles per hour = 148 ÷ 60 = 2.4667 miles per minute
2.4667 miles per minute = 2.4667 * 63360 = 156,288 inches per minute

```Circumference = diameter * pi
pi = 3.14159...........```
34.6 * 3.14159 = 108.699
Divide the speed of 156,288 inches per minute by the circumference of the wheel to get the revolutions per minute: 156,288 ÷ 108.699 = 1437.8

At a speed of 148 miles per hour, a wheel with a diameter of 34.6 inches will make 1437.8 revolutions per minute assuming no loss due to friction or load.

### MPH to RPM

Speed mph
Diameter in Inches in

#### Results:

 Circumference in Revolutions per Minute rpm

#### Calculation

1. speed in miles per hour
2. diameter in inches

#### Result

1. circumference in inches
2. revolutions per minute