Work out soil compaction instantly with clear inputs, formula shown and shareable results.
Relative compaction is field dry density divided by the maximum dry density obtained in a Proctor test, expressed as a percentage. Specifications normally require 95 percent of standard Proctor for general fill and 98 percent beneath pavements, because density controls settlement and shear strength directly.
Relative compaction
RC = field dry density / maximum dry density x 100
Required density
Required = maximum dry density x specified percentage
Preliminary estimate only. Compaction acceptance must follow the project specification and be based on properly conducted field density and laboratory Proctor tests.
RC = field dry density / maximum dry density x 100. Relative compaction is field dry density divided by the maximum dry density obtained in a Proctor test, expressed as a percentage.
Because the reference is the standard Proctor maximum. Modified Proctor energy or heavy field rollers can exceed it, so values of 100-104 percent of standard are common and acceptable.
This calculator takes 3 inputs: Field dry density, Maximum dry density from Proctor, Specified compaction. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.