Use the rotation speed converter to convert RPM, RPS, rad/s, deg/s, Hz, and rev/h for motors, fans, spindles, turntables, and machinery speed checks.
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Rotation speed converter Use this RPM converter to switch motor, spindle, fan, turntable, and drill speeds between RPM, revolutions per second, radians per second, degrees per second, hertz, and revolutions per hour.
Common presets
Magnitude-only converter
This tool treats rotation speed as a positive magnitude for equipment comparison. Use zero or greater values for motors, fans, turntables, spindles, and other machinery ratings.
Rotation speed converter: RPM, RPS, rad/s, degrees per second, and hertz explained
A rotation speed converter rewrites the same spin rate in the unit your job expects. This page also explains the main assumptions behind the rotation speed converter result, highlights the supporting figures shown by the calculator, and helps the reader use the estimate without overstating what a quick online tool can prove.
How rotational and angular units connect
One revolution contains 2π radians and 360 degrees. Once you know how many revolutions happen per second or per minute, every other supported unit is just a scaling step away.
That is why 60 RPM equals 1 revolution per second, 1 hertz, about 6.2832 rad/s, and 360 degrees per second. The object is not spinning differently; only the reporting convention changes.
The practical mistake is usually not the math. It is mixing unit styles across shop notes, PLC parameters, physics formulas, and instrument readouts. A clean rotation speed converter keeps those representations aligned so you can compare speeds without re-deriving the same 2π and 60-factor steps every time.
1 revolution = 2π rad = 360°
Links revolution-based and angle-based rotation units.
RPM = Hz × 60
Moves between cycles per second and cycles per minute.
rad/s = Hz × 2π
Converts a rotational frequency into angular speed.
RPM to rad/s, hertz, and time-per-revolution examples
Suppose a fan or shaft is turning at 60 RPM. Dividing by 60 gives 1 revolution per second, which is also 1 hertz. Multiplying that same rate by 2π gives about 6.2832 rad/s, and multiplying by 360 gives 360 degrees per second.
The reciprocal view is often just as useful. At 60 RPM, one full revolution takes 1 second. At 30 RPM, one revolution takes 2 seconds. At 3600 RPM, one revolution takes about 16.67 milliseconds. That period-style interpretation helps when you are checking indexing motion, camera pans, slow turntables, or how quickly a machine completes one full cycle.
Common benchmark speeds are easy to translate once the relationships are visible. A 33.33 RPM record player is about 0.5556 Hz and 3.4907 rad/s. A 1750 RPM motor is about 29.17 Hz and 183.26 rad/s. A 3600 RPM motor is 60 Hz and about 376.99 rad/s.
Hz = RPM / 60
Converts revolutions per minute into revolutions per second.
rad/s = RPM × 2π / 60
Converts RPM into the SI-style angular-speed form.
time per revolution = 1 / RPS
Expresses the same rotation rate as the duration of one full turn.
Rotation speed is not the same as linear surface speed
Two shafts can share the same RPM while their rim speeds are very different if the radii are different. Linear speed depends on both angular speed and radius, so RPM alone is not enough to describe belt speed, wheel speed, or tangential tool velocity.
That distinction matters in motors, turntables, grinders, and fans. Use this converter for the spin rate itself, then pair the result with a radius if you need a linear-speed calculation.
The same caution applies when users really need acceleration, torque, or power. Rotation speed tells you how fast the turning happens, not how hard the system is driving or how quickly the rate is changing.
Which unit should you use?
RPM remains the most familiar unit for motors, engines, fans, drills, and machine tools because it matches how manufacturers label rotational equipment. Hertz and revolutions per second are compact for instrumentation and signal-style reporting, while rad/s is the SI-friendly choice when the value needs to enter a physics or controls formula.
Degrees per second can be handy in robotics, camera motion, or navigation-style contexts where angular sweep is easier to visualise in degrees than radians.
If your number can be negative because direction matters, the angular velocity converter is the better fit. If you are comparing electronic, acoustic, or signal frequencies across hertz multiples and only occasionally need RPM or rad/s, the broader frequency converter is usually the better search-intent match. This page deliberately stays focused on positive rotation speed translation for machinery-style use cases.
NIST Special Publication 811 — NIST reference listing accepted unit relationships and SI usage conventions for angular and frequency-style quantities.
How to interpret slow versus fast rotation speeds
Slow equipment is often easier to understand in time-per-revolution terms. A display turning at 6 RPM completes one revolution every 10 seconds. A positioning table at 0.5 RPM takes 2 minutes per revolution. Those period checkpoints are often more intuitive than tiny hertz values when the motion is visibly slow.
Fast equipment is usually easier to compare in RPM or rad/s. A drill spindle at 10,000 RPM is easy to recognise in a workshop, while the equivalent 1047.2 rad/s is the cleaner form for equations. A good rotation speed converter should make both views available without forcing you to choose one mental model up front.
That is why this page includes both unit outputs and practical throughput interpretation. Seeing how many revolutions happen over 10 seconds, 1 minute, or 1 hour answers the next decision question after the conversion itself.
Frequently asked questions
How many RPM are in 1 hertz?
One hertz equals 60 RPM because hertz counts revolutions per second and RPM counts revolutions per minute. Multiplying by 60 converts seconds to minutes.
Why is rad/s different from RPM?
RPM counts full revolutions per minute. Rad/s measures angular change directly in radians per second. Since one revolution equals 2π radians, the two units differ by both the 2π factor and the time-unit conversion.
Can two machines with the same RPM have different tip speeds?
Yes. Linear surface speed depends on radius as well as angular speed. A larger wheel or blade moving at the same RPM covers more distance per second at its rim.
Is hertz the same as revolutions per second?
For simple rotational frequency, yes. Both describe one full revolution each second. The difference is mostly naming and context rather than magnitude.
How do you convert RPM to rad/s?
Multiply RPM by 2π and divide by 60. That converts full revolutions per minute into radians per second, because each revolution contains 2π radians and each minute contains 60 seconds.
What is the period of 60 RPM?
A speed of 60 RPM equals 1 revolution per second, so the period is 1 second per revolution. More generally, period is the reciprocal of revolutions per second.
Is RPM the same as Hz?
No, but they are directly related. RPM is revolutions per minute and Hz is revolutions per second for simple rotation. Dividing RPM by 60 converts it to Hz.
When should I use a rotation speed converter instead of an angular velocity converter?
Use a rotation speed converter when you mainly care about positive machine-speed magnitudes like fan speed, motor speed, spindle speed, or turntable speed. Use an angular velocity converter when sign, direction, or slower engineering time-base units matter in the calculation.
