Splitting a finished depth into lifts
Enter the compacted depth you have to end up with and the compacted thickness of one lift. The page rounds the lift count up, then reports the compacted thickness of the last lift, the spread thickness of each lift, the total spread depth and the loose volume. Spread thickness is the compacted thickness divided by one minus the settlement.
Lift thickness and settlement after compaction depend on the material, the roller and the site, and neither has been confirmed in an authoritative source. No reference figure is offered, so both are entered by you. Only thickness and volume definitions are used. Figures are current as of October 2026.
Compaction ratio verdicts, roller pass counts and material prices are not covered. Because the lift count rounds up, the last lift can be thinner than the lift thickness entered. This calculator is for reference and does not replace design work; review by a qualified engineer is required.
Frequently Asked Questions
The count has to be a whole number and the finished depth has to be reached, so it rounds up. The last lift then ends up thinner than the lift thickness you entered.
Use the value measured on a test strip. No authoritative figure is offered here, and entering 0 makes the spread thickness equal the compacted thickness.
No. It is the entered area multiplied by the total spread depth only; hauling and placement losses are not covered.