This work describes a simple method for estimating Boltzmann constant using a computer-based data acquisition system. This procedure consists of measuring the volume and pressure of hydrogen gas obtained through the electrolysis of water during a known time interval. The electrical charge is calculated by the software in real-time from the collection of data current as a function of time. This laboratory experiment is fast and sufficiently accurate to estimate Boltzmann constant, in which the percentage error was approximately 0.3 % of the accepted value. Discussion of the experimental procedure and the results obtained for different trials are presented.