$$ P = \Gamma.\omega = \frac{2\pi}{60}.\Gamma.N$$
where:
\( P \) is the power expressed in Watts ( \( W \) )
\( \Gamma \) is the torque expressed in \( N.m \)
\( \omega \) is the angular velocity in \( rad.s^{-1} \)
\( N \) is the angular velocity in revolution per second ( \( rpm \) )