The Widmark formula for alcohol quantification.

In 1932 the Swedish scientist Eric P Widmark developed two formulae commonly used for the calculation of the amount of alcohol ingested and for assessing the concentration of alcohol at some time prior to the sampling. The most important statement in the respect to these calculations is to stress the unreliability and inaccuracy of attempting back-calculations in either direction. Only gross approximations can be achieved and no pretence at accuracy must be offered.