In cycling, the power you put into the pedals is measured in watts. Ideally, each watt is used to move you forward, but in reality, only a portion of those watts are used for that purpose and there are losses along the way. As a cyclist, every watt you haven’t lost counts towards how fast you’re going.
There are four main components that make up the the watts required for you to ride a bike at a specific velocity. The equation below is taken from the Chung Method.