Heat duty calculator is a free software to help with computing the sensible heat duty and the latent heat transfer rate, the calculator uses the equations stated in the article available at WeBBusterZ Engineering Articles website. This article titled "How to calculate the heat duty". The software can accept input in SI Units or English Units of measurement. The flow rate can be specified by volume or mass flow. The answer will be shown in several units Flow rate input units - m3/s, m3/h, m3/day, ft3/s, ft3/h, ft3/day, kg/s, kg/h, kg/day, lb/s, lb/h, lb/day The output heat rate (Duty) is calculated in kW, Btu/h, hp (British), hp (Metric).