An apparatus for measuring the force of ejaculation including a cylinder having a length and an internal diameter sufficient to enclose an erect male penis, a groove track extending along at least part of the length of the cylinder, a membrane positioned within the cylinder and oriented substantially perpendicularly to the length of the cylinder, and a connector slide connected to the membrane, the connector slide being configured to suspend the membrane within the cylinder and to slide along groove track as the membrane is caused to moved lengthwise within the cylinder. A method of evaluating the force of ejaculation using the apparatus including inserting a penis into the cylinder and measuring the distance the membrane is propelled lengthwise within the cylinder by the force of semen ejected from the penis.
