A simple, versatile, magnetic float densimeter that can be used to measure the density of liquids as a function of temperature is described. The system has been calibrated with water from 20 to 50°C demonstrating a sensitivity of 0.3 ppm and a precision of 2 ppm. The accuracy of the densimeter has been verified by measuring the densities of NaCl solutions at 25°C. Excellent agreement with previously published data was achieved.