The purpose of this paper is to calculate a method of estimating minimum dairy farm sizes for specific income levels. A survey of a sample of Utah dairy farmers was conducted to obtain data to calculate a long run average cost schedule. Dairy farmers who had just recently built new facilities and with varying sized herds were interviewed. Individual costs were studied to establish their effect on the long run average cost curve. Different average revenue curves for varying prices and production levels were used to establish minimum cow numbers needed to give s pecified incomes and growth potentials. Marginal analysis was used to establish the most efficient methods of growth, i.e., cow numbers, herd production and blend price.