The conventional practice of expressing the relationship between volume flow rate,Q, and frequency,f(or pulse rate) for turbine flow meters by the ‘‘Kfactor’’ is examined. Curvature in plots ofKagainstfdue to the existence of a nonzero intercept in the linear equation relatingftoQis illustrated using calibration (water and type II hydrocarbon) data. An algorithm which enables the actual linear range of turbine flow meters to be simply and easily ascertained is presented. The very significant improvement in linearity accomplished by the use of the algorithm is illustrated for the calibration data.