Abstract The pulse-height defect (PHD) of a Si surface barrier detector (1000 ωcm resistivity) has been measured with a cyclotron for elements from Kr to Au between energies of 15 to 160 MeV, and for elements from Ne to Fe between 5 and 50 MeV. A simple power-law formula for relating the PHD to the total energy is described. A procedure for calibrating a Si detector for the PhD from measurements for several elements has been developed and tested. This procedure reproduces the data to within the experimental error (±0.5% of the total energy). Application of the measured and calculated PHD values to another detector of similar resistivity seems to be accurate to better than 10% of the PHD. Our PHD data are also compared to an existing PHD formalism.