Abstract: Noncombustive method of measuring the calorific value of fuel gas, wherein a) the speed of sound in the gas is determined under first and under second reference conditions and one of the parameters dielectric constant, speed of sound under third reference conditions or proportion of carbon dioxide in the fuel gas is measured and b) the calorific value is derived from these three parameters, wherein the steps a) and b) are preferably preceded by a plurality of measurement cycles in which step a) is carried out using a plurality of reference gases of known calorific value, a number corresponding to the number of measurement cycles of reference signal patterns determined from the ratio of the various measurement signals measured on the reference gases are stored with assignment to the known calorific values and the signal pattern from a future measurement cycle on fuel gas of unknown calorific value is compared with the reference signal patterns so as to assign a particular calorific value.