A capacitive extensometer has an extensometer frame formed of a pair of arms connected together about a hinge axis at first remote ends, and having second ends which include specimen contacting members for engaging the surfaces of a specimen to be tested. A capacitive type sensing arrangement is mounted on the arms, and is used with conventional circuitry for determining arm motion. The sensing is made so that it can be compensated for nonlinearities and minimizes undesirable extraneous effects by utilizing concave and convex shaped mating surfaces on the sensing elements. The ability to mount and protect the capacitor sensor approximately, while obtaining a relatively large output signal enhances the operability of the extensometer.