Physics
Torque and power
Power is torque times rotational speed, which is why gearing trades speed against turning force.
The Formula
P = tau x angular velocity
Power is torque times rotational speed, which is why gearing trades speed against turning force.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| P | Power | watts | Rate of doing rotational work. |
| tau | Torque | newton metres | Turning effect. |
| omega | Angular velocity | rad/s | Rotational speed in radians per second. |
What Each Symbol Means
Pwatts
Power
Rate of doing rotational work.
taunewton metres
Torque
Turning effect.
omegarad/s
Angular velocity
Rotational speed in radians per second.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate torque page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate Torque, filed under Science. Every number the guide produces comes from substituting into this one line.