The aim was to determine the light intensity emitted by candles made of paraffin, beeswax, fat and stearic acid. In order to be able to reach a conclusion regarding how effectively combustion occurs with these different candle materials, an apparatus was developed which allowed wax consumption rates and light intensity to be determined simultaneously. The relationship between these two factors (light intensity/wax consumption) can be used to provide a unit of measurement for the effectiveness of the transformation of chemical energy into light.