This method describes the procedure for determining the relative compaction and/or the difference between the optimum moisture content and the field moisture content of a soil by relating 'converted' wet density and 'added' moisture without the immediate need to determine the moisture content. It is a rapid method. Usually the results of only three compacted test specimens are required and both the test and the calculations can be done in less than an hour. The control parameters are determined either for the total material or for the material finer than a specified BS sieve. Because it is a rapid method the refinement of proper curing is necessarily omitted. There is also some relaxation in the maximum particle size to allow compaction of material up to 1-inch size. These relaxations may result in minor differences between results obtained from Tests 11A and 12A, especially in more cohesive soils and soils with a rock fraction. The test may be used for checking material before placement to ensure that the moisture content is within specified limits.