Unit Conversion & Lookup Matrix
Gravel Compaction & Settlement Calculator
Calculate compaction shrinkage ratios and loose vs compacted depth for dense grade base aggregates and crusher run.
📐 Mathematical Conversion Formula:
Loose Depth Required = Desired Compacted Depth × Compaction Multiplier (1.10 to 1.25) Reference Conversion Table & Examples
Calculations are based on standard quarry aggregate testing weights at ambient moisture levels.
| Aggregate Material | Target Compacted Depth | Compaction Loss | Loose Depth to Install |
|---|---|---|---|
| Crusher Run / DGA | 4 inches | 20% compaction | 4.8 inches loose |
| Crushed Stone #57 | 4 inches | 12% compaction | 4.5 inches loose |
| Decomposed Granite | 3 inches | 18% compaction | 3.5 inches loose |
| Pea Gravel (Round) | 3 inches | 5% settlement | 3.15 inches loose |
Standard Density Factors by Aggregate Type
Use these verified density constants to perform custom volume-to-weight conversions:
| Aggregate Material | Density (lbs/cu yd) | Tons per Cu Yd | Tons to Yds Multiplier |
|---|---|---|---|
| Pea Gravel (3/8") | 2800 lbs/yd³ | 1.4 t/yd³ | 0.71 yds/ton |
| Crushed Stone #57 (1/2" - 1") | 2700 lbs/yd³ | 1.35 t/yd³ | 0.74 yds/ton |
| Crusher Run / Dense Grade (DGA) | 3000 lbs/yd³ | 1.5 t/yd³ | 0.67 yds/ton |
| River Rock (1" - 3") | 2600 lbs/yd³ | 1.3 t/yd³ | 0.77 yds/ton |
| Decomposed Granite (DG) | 3000 lbs/yd³ | 1.5 t/yd³ | 0.67 yds/ton |
| Drain Rock / Drainage Gravel (1" - 1.5") | 2600 lbs/yd³ | 1.3 t/yd³ | 0.77 yds/ton |
| Lava Rock (Red / Black) | 1200 lbs/yd³ | 0.6 t/yd³ | 1.67 yds/ton |
Frequently Asked Questions About Gravel Compaction Calculator
How much does gravel shrink when compacted with a plate compactor?
Angular aggregates with fine dust (like Crusher Run or road base) compact by 15% to 22%. Clean open-graded stones like #57 stone compact by only 8% to 12%.
How do you compact gravel properly?
Spread gravel in layers (lifts) no thicker than 2 to 3 inches at a time, lightly spray with water to facilitate particle alignment, and make 3 to 4 passes with a vibrating plate compactor.
Missing a Stone Type or Have Feedback?
We update density presets and formulas regularly based on local quarry feedback.