The present invention relates to a method for calibrating milk meters in a milking system comprising a milking station (10a, 10b; 20) having at least one milk meter (14a,14b; 21a, 21b, 21c, 21d) that measures a value of a milking performance of a milking animal. The method comprises the steps: determining a reference value which reflects the amount of milk received from a number of milking animals during a selected time period in a reference unit (19; 32), retrieving all measured values during the selected time period for each milk meter (14a, 14b; 21a, 21b, 21c, 21d) that by itself contribute to the amount of milk received by the reference unit (19; 32), comparing the reference value with the sum of all retrieved measured values and calculating a correction function for one of the milk meters, and using the calculated correction function to adjust the measured value from the milk meter.