A distributed array of force sensors disposed in the inner lining of a safety helmet measure forces between the inner periphery of the helmet and a user's head, and a microcontroller responsive to the force measurements and other sensor data determines if the helmet fits the user properly. The force sensors are preferably provided at the front, back, sides and top of the inner lining, and the microcontroller compares the measured forces to calibrated threshold values to evaluate and indicate the fit of the helmet.