Calculate revolutions per second, minute, or hour from one known value and time unit, then find the equivalent rate in another unit.
Revolutions Per Hour Formula
The calculator converts a rotation rate from one time unit to another. It uses seconds as the common time base.
R_out = R_in * T_out / T_in
- R_out = converted rotation rate, in revolutions per selected output time unit
- R_in = entered rotation rate, in revolutions per selected input time unit
- T_out = number of seconds in the output time unit
- T_in = number of seconds in the input time unit
For revolutions per hour, the common formulas are:
RPH = RPS * 3600
RPH = RPM * 60
- RPH = revolutions per hour
- RPM = revolutions per minute
- RPS = revolutions per second
If you enter one rotation rate, the calculator fills in the missing rate using the selected time units. For example, it can convert revolutions per minute to revolutions per hour, revolutions per second to revolutions per hour, or revolutions per hour back to revolutions per minute or second.
Revolution Rate Conversion Factors
Use these factors to check common conversions.
| Starting unit | To revolutions per hour | Example |
|---|---|---|
| Revolutions per second | Multiply by 3,600 | 2 rev/s = 7,200 rev/hr |
| Revolutions per minute | Multiply by 60 | 120 rev/min = 7,200 rev/hr |
| Revolutions per hour | No change | 7,200 rev/hr = 7,200 rev/hr |
Seconds in Each Time Unit
| Time unit | Seconds in unit | Use in formula |
|---|---|---|
| Second | 1 | T = 1 |
| Minute | 60 | T = 60 |
| Hour | 3,600 | T = 3,600 |
Example Calculations
Example 1: Convert revolutions per minute to revolutions per hour
You have a rate of 90 revolutions per minute.
RPH = RPM * 60
RPH = 90 * 60 = 5400
The result is 5,400 revolutions per hour.
Example 2: Convert revolutions per second to revolutions per hour
You have a rate of 3 revolutions per second.
RPH = RPS * 3600
RPH = 3 * 3600 = 10800
The result is 10,800 revolutions per hour.
FAQ
How do you convert RPM to revolutions per hour?
Multiply RPM by 60. There are 60 minutes in one hour, so a rate of 1 revolution per minute equals 60 revolutions per hour.
How do you convert revolutions per hour to RPM?
Divide revolutions per hour by 60. For example, 7,200 revolutions per hour divided by 60 equals 120 revolutions per minute.
Is revolutions per hour the same as total revolutions?
No. Revolutions per hour is a rate. It tells you how many revolutions happen in one hour. Total revolutions is a count. If a machine runs at 500 revolutions per hour for 3 hours, the total is 1,500 revolutions.
