Thin film stress gauges for the measurement of stress waves in solids are calibrated in a uniaxial strain field where the lateral strain components are zero. Frequently, measurements of stress are needed in situations where the lateral strain components are nonzero. The analysis of data often becomes that of best guess, or whatever seems most reasonable. This work is an attempt to quantify the effect of strain on stress gauge output, and to present a technique for strain compensation. To accomplish this, the theories of piezoresistive and piezoelectric films are used to develop equations of the gauge output in terms of normal stress and two components of lateral strain. Thus, with two strain gauges and one gauge that reads stress plus strain, a time‐resolved stress history can be accurately determined. ©1995 American Institute of Physics.