About this tool
Angular Velocity & RPM Calculator is a free, in-browser tool that converts between the four ways of describing rotation — angular velocity ω, revolutions per minute, frequency and period — and, given a radius, the tangential speed and centripetal acceleration of a point on the rotating body. Enter any one value and read the rest instantly. Nothing is uploaded.
The conversions all follow from ω = 2π·f = 2π ÷ T = 2π·RPM ÷ 60, where f is frequency in hertz and T is the period in seconds. From ω the tool recovers frequency f = ω ÷ 2π, speed RPM = ω·60 ÷ 2π and period T = 1 ÷ f. If you supply a radius r, the tangential (linear) speed is v = ω·r and the centripetal acceleration toward the centre is a = ω²·r.
Use it for motors, wheels, turntables and orbital problems — for instance 3000 RPM is about 314.16 rad/s, 50 Hz and a 0.02 s period. Add a radius to see how fast the rim actually moves and the acceleration holding it in its circle.