Turns Per Second
A wheel that makes 5 turns each second runs at 300 RPM.
Quick answer: Multiply the turns per second by 60. For example, 5 rev/s is 300 RPM, 50 rev/s is 3,000 RPM and 500 rev/s is 30,000 RPM.
The turns per second to RPM formula
Speed in RPM equals turns per second times 60.
A turn and a revolution are the same thing.
Take 5 rev/s. 5 × 60 gives 300 RPM.
Take 50 rev/s. 50 × 60 gives 3,000 RPM.
Turns and revolutions
One turn is one full circle of 360 degrees. Counting the turns in one second and multiplying by 60 gives the turns in one minute.
Turns per second is handy when you can count a fast spin by eye or by slow motion video.
How to convert turns per second to RPM step by step
- Read the turns per second.
- Multiply by 60.
- Round to the digits you need.
- Write RPM after the answer.
Example 1: 5 rev/s
- Start with 5 rev/s.
- 5 × 60 = 300.
- The rotation rate is 300 RPM.
5 rev/s = 300 RPM
Example 2: 50 rev/s
- Start with 50 rev/s.
- 50 × 60 = 3,000.
- The rotation rate is 3,000 RPM.
50 rev/s = 3,000 RPM
Example 3: 500 rev/s
- Start with 500 rev/s.
- 500 × 60 = 30,000.
- The rotation rate is 30,000 RPM.
500 rev/s = 30,000 RPM
Example 4: 25 rev/s
- Start with 25 rev/s.
- 25 × 60 = 1,500.
- The rotation rate is 1,500 RPM.
25 rev/s = 1,500 RPM
Example 5: 250 rev/s
- Start with 250 rev/s.
- 250 × 60 = 15,000.
- The rotation rate is 15,000 RPM.
250 rev/s = 15,000 RPM
Example 6: 10 rev/s
- Start with 10 rev/s.
- 10 × 60 = 600.
- The rotation rate is 600 RPM.
10 rev/s = 600 RPM
Round only at the end. Rounding in the middle of a sum adds small errors that grow.
turns per second to RPM conversion table
| Turns per second (rev/s) | Revolutions per minute (RPM) | Degrees per second (deg/s) |
|---|---|---|
| 0.5 rev/s | 30 RPM | 180 Degrees per second (deg/s) |
| 1.25 rev/s | 75 RPM | 450 Degrees per second (deg/s) |
| 2.5 rev/s | 150 RPM | 900 Degrees per second (deg/s) |
| 5 rev/s | 300 RPM | 1,800 Degrees per second (deg/s) |
| 10 rev/s | 600 RPM | 3,600 Degrees per second (deg/s) |
| 25 rev/s | 1,500 RPM | 9,000 Degrees per second (deg/s) |
| 50 rev/s | 3,000 RPM | 18,000 Degrees per second (deg/s) |
| 100 rev/s | 6,000 RPM | 36,000 Degrees per second (deg/s) |
| 250 rev/s | 15,000 RPM | 90,000 Degrees per second (deg/s) |
| 500 rev/s | 30,000 RPM | 180,000 Degrees per second (deg/s) |
| 1,250 rev/s | 75,000 RPM | 450,000 Degrees per second (deg/s) |
| 2,500 rev/s | 150,000 RPM | 900,000 Degrees per second (deg/s) |
The highlighted row is the default of the calculator. The last column gives Degrees per second (deg/s).
A quick mental shortcut for turns per second to RPM
Count the turns in a second and multiply by 60. Three turns a second is 180 RPM.
Add a zero for tens: 10 turns a second is 600 RPM.
Counting turns
Film a spinning part at a known frame rate and count the frames per turn. Divide the frame rate by the frames per turn to find turns per second.
Then multiply by 60 for RPM.
Degrees per second
One turn each second is 360 degrees each second. The last column gives the speed in degrees per second.
Use it for pointing and aiming tasks.
Same as hertz
For a rotating part, turns per second and hertz are the same number. The Hz to RPM page covers frequency from sensors.
Both use the factor of 60.
Quick conversion answers
| Conversion | Result |
|---|---|
| 5 rev/s | 300 RPM |
| 50 rev/s | 3,000 RPM |
| 500 rev/s | 30,000 RPM |
| 5,000 rev/s | 300,000 RPM |
Where this conversion is used
Hobbyists measure the speed of fans and propellers.
Students convert spin rates.
Common mistakes to avoid
- Dividing by 60. That turns RPM into turns per second.
- Mixing turns and radians. One turn is 2 pi radians.
- Counting half turns. Count full circles.
- Forgetting the unit. Write RPM or rev/s.
Related converters
More values at a glance
0.1 rev/s is 6 RPM. 1.5 rev/s is 90 RPM. 3.75 rev/s is 225 RPM.
7.5 rev/s is 450 RPM. 15 rev/s is 900 RPM. 20 rev/s is 1,200 RPM.
75 rev/s is 4,500 RPM. 125 rev/s is 7,500 RPM. 1,000 rev/s is 60,000 RPM.
Common spin rates
0.5 rev/s is 30 RPM. 1 rev/s is 60 RPM. 2 rev/s is 120 RPM.
3 rev/s is 180 RPM. 10 rev/s is 600 RPM. 15 rev/s is 900 RPM.
20 rev/s is 1,200 RPM. 50 rev/s is 3,000 RPM. 100 rev/s is 6,000 RPM.
More worked values
1 rev/s is 60 RPM. 2 rev/s is 120 RPM. 4 rev/s is 240 RPM.
8 rev/s is 480 RPM. 15 rev/s is 900 RPM. 25 rev/s is 1,500 RPM.
40 rev/s is 2,400 RPM. 75 rev/s is 4,500 RPM. 100 rev/s is 6,000 RPM.
Going the other way
To turn RPM back into rev/s, do the opposite step.
1 RPM is 0.016667 rev/s. 5 RPM is 0.083333 rev/s. 10 RPM is 0.166667 rev/s.
20 RPM is 0.333333 rev/s. 50 RPM is 0.833333 rev/s. 100 RPM is 1.666667 rev/s.
250 RPM is 4.166667 rev/s. 500 RPM is 8.333333 rev/s.
A full worked example
Take 7.5 rev/s. Multiply by 60 to get 450 RPM.
Now check it. Turn 450 RPM back into rev/s and you should land on 7.5 again.
If you do not, look for a slipped decimal point or a swapped unit.
Rounding the answer
Keep about as many digits as your input has. For example, 12.3456 rev/s is 740.736 RPM, which is 740.74 RPM to 2 decimals.
Round only at the end. Rounding early can add a small error to the final number.
Small and large values
0.1 rev/s is 6 RPM. 0.25 rev/s is 15 RPM. 0.5 rev/s is 30 RPM.
3 rev/s is 180 RPM. 6 rev/s is 360 RPM. 12 rev/s is 720 RPM.
30 rev/s is 1,800 RPM. 60 rev/s is 3,600 RPM. 150 rev/s is 9,000 RPM.
200 rev/s is 12,000 RPM. 300 rev/s is 18,000 RPM. 400 rev/s is 24,000 RPM.
More values in the reverse direction
2 RPM is 0.033333 rev/s. 3 RPM is 0.05 rev/s. 25 RPM is 0.416667 rev/s.
30 RPM is 0.5 rev/s. 40 RPM is 0.666667 rev/s. 60 RPM is 1 rev/s.
75 RPM is 1.25 rev/s. 200 RPM is 3.333333 rev/s. 400 RPM is 6.666667 rev/s.
1,000 RPM is 16.666667 rev/s.
Frequently asked questions
How many Revolutions per minute is 1 rev/s?
1 rev/s is 60 RPM.
How many Revolutions per minute is 50 rev/s?
50 rev/s is 3,000 RPM.
How many Turns per second is 1 RPM?
1 RPM is 0.01666667 rev/s.
How many RPM is 10 turns per second?
600 RPM.
How many turns per second is 1,200 RPM?
20 turns per second.
How many degrees per second is 5 turns per second?
1,800 degrees per second.
Sources
- Lucidar: rpm to m/s converter (lucidar.me)
