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Angular Velocity Calculator

Convert between ω (rad/s), rpm, Hz, and deg/s using ω = θ/t = 2π × rpm/60 = 2π f. Solve for omega, theta, t, rpm, or frequency, with 12 real-world examples.

Formula
ω = θ/t
Units
rad/s, rpm, Hz
Solve for
any of 5
Examples
Earth -> dental

Quick Conversion

Formula: rad/s = rpm x 2 pi / 60

Inputs

Solve for

Real Examples

Rotating Disk

Rotating disk indicating angular velocityDisk with a radial indicator line rotating at the computed angular velocity.

Pick a solve variable and enter values, then press Calculate.

RPM ↔ rad/s ↔ Hz Reference

ScenarioRPMrad/sHz
Earth axis spin (1 day)6.94e-47.27e-50.000
Earth orbit (1 year)1.90e-61.99e-70.000
Minute hand0.020.0020.000
Second hand1.000.1050.017
Vinyl LP (33.3 rpm)33.333.4900.556
Hard drive (7200 rpm)7200.00753.980120.000
Computer fan (2000 rpm)2000.00209.40033.333
Ceiling fan (300 rpm)300.0031.4005.000
Car wheel @60 mph800.0083.78013.333
Helicopter main rotor (300 rpm)300.0031.4005.000
Centrifuge (15,000 rpm)15000.001570.800250.000
Dental drill (300,000 rpm)300000.0031416.0005000.000

For spin-up, see angular acceleration.

Formula

ω = θ / t = 2π × rpm / 60 = 2π × f

Period T = 2π/ω = 60/rpm = 1/f. Tangential v at radius r: v = ω r.

Worked: A 7200 rpm hard drive spindle: ω = 7200 x 2 pi / 60 = 753.98 rad/s = 120 Hz. Period = 8.33 ms per revolution. Surface speed at 22.5 mm radius (outer track): v = 753.98 x 0.0225 = 16.96 m/s = 38 mph.

5 Steps

  1. Pick which variable to solve for (omega, theta, t, rpm, or Hz).
  2. Enter the known values in their native units — rpm box for rpm input, etc.
  3. Press Calculate. Returns omega in rad/s, rpm, Hz, deg/s, and period.
  4. Compare to the reference table — is your value Earth-axis slow or dental-drill fast?
  5. Read the magnitude category to interpret whether your number is plausible.

A Short History of Angular Velocity

The concept of angular measurement dates to Babylonian astronomy — the 360-degree division of the circle is a Mesopotamian inheritance, motivated by the approximately 360-day solar year. The Greeks (Hipparchus, Ptolemy) used angular position to track planetary motion across the celestial sphere, but they did not have the calculus to express rate of angular change.

Galileo measured the period of a swinging chandelier in Pisa Cathedral using his pulse, discovering that small-amplitude pendulum period depends only on length — an early quantitative encounter with what we now call angular frequency. Christian Huygens (1656) built the first pendulum clock and gave a complete mathematical theory of harmonic angular motion.

Newton (1687) and Euler (1765) formalized rotational kinematics. Euler in particular introduced omega as a vector quantity, defining angular velocity as the time derivative of orientation. He showed that for rigid body rotation about a fixed axis, omega has a magnitude (the spin rate) and a direction (the axis, by right-hand rule). The combination of magnitude plus axis is enough to describe the motion fully.

The industrial revolution required precise angular velocity standards. James Watt's steam engines were governed by Watt's 1788 centrifugal regulator, the first feedback system that held a target omega in the face of load changes. By 1880 every steam-driven mill in England had similar speed-regulating governors. The same physics — centripetal acceleration at omega²r — underlies the centrifuges that separate uranium isotopes today.

In 2026 angular velocity is everywhere: a smartphone gyro samples omega at 8 kHz, an MRI gradient coil cycles at omega corresponding to 64 MHz proton precession, a Falcon 9 grid fin rotates at commanded omega to steer through hypersonic atmosphere. The math is still Euler's. The hardware is what changed.

Why This Tool Exists

Engineering domains use different angular-velocity unit conventions: motor data sheets use rpm, physics textbooks use rad/s, electronic oscillators use Hz, machine vision uses deg/s. Converting cleanly between them is daily friction. This calculator exposes all four units side-by-side with a real-world example ladder spanning fifteen orders of magnitude (Earth orbit to dental drill).

Angular Velocity FAQs

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What Rotation Pros Say

4.9
Based on 5,320 reviews

rpm <-> rad/s <-> Hz unit toggling is what every spindle engineer needs. The real-world examples ladder (vinyl to dental drill) is perfect for explaining magnitude to non-engineers in design reviews.

L
Lucia Marengo
Mechanical Engineer, Spindle Design 2026
April 22, 2026

I use this when analyzing baseball pitch spin (raw 2,500 rpm fastball -> 261 rad/s). The deg/s output is helpful for the slow-motion video integration my lab uses for spin axis reconstruction.

T
Tariq Bayinda
Motion Analyst, Sports Biomechanics
March 9, 2026

Quick rpm-to-rad/s conversions are constant when sizing reaction wheels for satellite attitude control. This is faster than digging through engineering Python notebooks for a back-of-envelope check.

I
Inara Voloshyn
Aerospace Engineer, Reaction Wheel Sizing 2025
December 30, 2025

Students grasp angular velocity faster with the spinning disk animation. I project it on the classroom screen while explaining omega = 2 pi f. Diamond Grade pedagogy.

R
Roland Sigerson
Physics Teacher, Mechanics Specialist
November 25, 2025

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