A method for estimating non-commercial energy consumption in the household sector of developing countries is presented. It has been observed that the energy demand for cooking is not income-elastic. The average requirement per person and hence the total requirement, both in useful energy terms, can be determined. The actual total commercial energy consumption for cooking is converted to useful energy terms and subtracted from this total to give a residual which is the estimated total amount of non-commercial energy used for cooking. The residual may be converted to delivered or primary energy by using an appropriate conversion factor. Using this method, the annual consumption of non-commercial energy has been estimated for selected Southeast Asian countries between 1960 and 1980.