A flywheel measuring system includes a base, a flywheel, at least one permanent magnet, a magnetic core, an abutting member fixed on the base, a cantilever arm, and a signal generating apparatus. The flywheel is rotatably disposed on the base and is provided with at least one permanent magnet. The magnetic core is movably disposed on the base and is electromagnetically coupled to the at least one permanent magnet. The cantilever arm is disposed on the base. The signal generating apparatus is disposed on the cantilever arm. When the flywheel rotates, the at least one permanent magnet drives the magnetic core to move, and the magnetic core pushes the cantilever arm to approach the abutting member, so that the signal generating apparatus generates a strain and outputs a signal. The fitness equipment could calculate an output power when a rider pedals the pedal according to the signal.
