The paper presents a simple and efficient economic dispatch algorithm suitable for unit commitment. It also caters for any combination of polynomial cost functions. The algorithm reduces the economic dispatch into an equivalent lossless problem from which solutions are easily obtained and analytically. The equivalent lossless problem enables the generators whose outputs violate their limit constraints to be handled efficiently and correctly. The algorithm can cater for both theBmatrix and Jacobian matrix loss formulation. Case studies with various test systems are presented and discussed.