Measurements have been made of the functional form of the energy-differential cross sections for carbon, using transmission electron energy-loss spectroscopy. It is shown that both the characteristic K edge and the background, prior to the K edge, can be represented accurately by functions of the form AE−r, where E is the energy loss and A and r are constants. The values of the exponent in this expression for the K edge have been compared with calculated values derived from a hydrogenic model and good agreement has been obtained.