Equilibrium output is an economics term for finding the output where demand equals supply. Your demand and supply function will look something like demand equals 30-10P and supply equals 3+14P, where "P" is the output level. These numbers represent your demand and supply curves. To find where the equilibrium is, you can either graph the functions and mark where they meet, or you can set the two functions equal to each other.
Determine your supply and demand curve functions. For example, assume your functions are 30-10P and 3+14P.
Set the two functions to equal each other. In the example, 30-10P=3+14P.
Solve your new equation. In the example 30-10P=3+14P, "P" equals 1.125.