Diamagnetic materials create magnetic fields that opposes an externally applied magnetic field. Water is a diamagnetic material. However, the interaction is extremely weak, and visually noticeable effects can only be obtained using powerful superconducting magnets. In the past, demonstrations of diamagnetism in water using more accessible permanent magnets have been qualitative. The goal of the experiment was to quantify the diamagnetic effect of a permanent magnet on water using techniques accessible at a high school or introductory college physics level.