To maximize crop productivity and minimize adverse environmental effects, it is critical that land applications of manures meet, but not exceed, crop nutrient requirements. To assure that the actual manure application rate matches the desired application rate, manure-spreading equipment must be calibrated. The goal of manure spreader calibration is to determine the amount of manure, on a weight per unit area basis, that is being applied to a field. This publication describes three methods for manure spreader calibration for spreaders handling solid and semi-solid manures.