A method of controlling a supply of a fuel to a combustor of a gas turbine having a compressor upstream of the combustor is provided. The method includes: supplying the fuel to the combustor; obtaining a property value of at least one physical property (PT8, PT7, Tinlet, THBOV) of air used for burning the fuel in the combustor; estimating a heat input (HIengmodel) of the fuel supplied to the combustor based on the property value; measuring a Caloric Value (LCVmea) of the fuel upstream of the combustor; adjusting the estimated heat input (HIengmodel) based on the measured Caloric Value (LCVmea); and controlling a fuel valve regulating the supply of the fuel to the combustor based on the adjusted estimated heat input (HIexpected) and a demanded heat input (FFDEM).