Stone Compaction Calculator
Factor in material compaction for a more accurate volume estimate.
Compaction Details
1. Enter Loose Volume & Material
Understanding the Stone Compaction Calculator
The stone compaction calculator is a professional-grade tool that helps you understand one of the most overlooked aspects of building a proper foundation: the difference between loose and compacted volume. When you order 10 cubic yards of crushed stone, that is its 'loose' volume in the truck. Once you spread and compact it with a plate compactor, its volume will decrease.
This calculator shows you the estimated final 'compacted' volume based on the material type. Materials like crushed stone or stone dust can see a volume reduction of 15-25%. Failing to account for this means your 4-inch base could easily end up being only 3 inches deep. This tool is crucial for ensuring your finished project has the structural integrity you planned for.
Frequently Asked Questions
What is the compaction rate of crushed stone?
Crushed stone typically compacts to about 80-85% of its loose volume, which is a compaction factor of 1.15 to 1.25. This means you need to order about 20% more material than your final, compacted volume calculation.
Why is compacting stone so important?
Compaction forces the angular pieces of stone to interlock, creating a dense, stable base that distributes weight evenly. An uncompacted base will settle over time, leading to sinking patios, uneven walkways, and rutted driveways.
How do you use a plate compactor?
For best results, spread the stone in 2-3 inch layers (lifts). Lightly moisten each layer with a hose, then go over it 2-3 times with the plate compactor until the material is firmly locked in place. Repeat for each layer.
Which materials compact the most?
Materials with a mix of particle sizes and angular shapes, like crushed stone and especially stone dust, compact the most. Rounded, uniform materials like pea gravel or river rock show very little compaction.
What is "loose volume" vs "compacted volume"?
Loose volume is the space the material takes up when it's just been dumped from a truck. Compacted volume is the smaller space it takes up after being mechanically pressed down, removing the air pockets between the stones.
How does this calculator help me order?
It helps you work backwards. If you know you need a final, compacted base of 5 cubic yards, this tool can estimate that you should actually order around 6.25 cubic yards of loose material to achieve that final depth.