Field Guide
How Much Gravel Do I Need? The Complete US Contractor & DIY Guide
Whether you're ordering a tri-axle of crusher run for a new driveway or picking up a few bags of pea gravel for a garden path, the math is the same: measure the volume, account for compaction, and convert to weight using the right aggregate density.
1. How to Calculate Gravel Tonnage (The Math Explained)
Gravel is sold by volume (cubic yards) or by weight (short tons). Your measurements come in feet and inches, so you'll convert in four steps. Here's the exact process this calculator uses.
-
1
Convert depth from inches to feet
Depth is usually specified in inches, but length and width are in feet. Divide inches by 12.
Depth (ft) = Depth (in) ÷ 12 Example: 4 in ÷ 12 = 0.333 ft -
2
Calculate cubic feet
Multiply the three dimensions together to get the raw (loose) volume.
Cubic Feet = Length (ft) × Width (ft) × Depth (ft) Example: 50 × 12 × 0.333 = 200 ft³ -
3
Add compaction & waste, then convert to cubic yards
Loose stone settles and compacts. Add a factor (typically 5–15%), then divide by 27 — there are 27 cubic feet in one cubic yard (3 ft × 3 ft × 3 ft).
Final Volume = Raw Volume × (1 + Compaction % ÷ 100) Cubic Yards = Final Cubic Feet ÷ 27 Example: 200 × 1.10 = 220 ft³ → 220 ÷ 27 = 8.15 yd³ -
4
Convert cubic yards to tons
Multiply by the material's density in tons per cubic yard. US quarries sell by the short ton (2,000 lbs), not the metric tonne (2,204.6 lbs).
Tons = Cubic Yards × Density (tons/yd³) Example (Crusher Run @ 1.60): 8.15 × 1.60 = 13.04 tons Pounds = Tons × 2,000 = 26,080 lbs
Quick unit conversions
- 1 cubic yard = 27 cubic feet
- Density (lbs/ft³) = Density (tons/yd³) × 2,000 ÷ 27 ≈ tons/yd³ × 74.07
- Density (tons/yd³) = Density (lbs/ft³) × 27 ÷ 2,000 = lbs/ft³ × 0.0135
- One 50 lb retail bag ≈ 0.5 cubic feet of gravel
2. Aggregate Density Quick-Reference Table
Average dry, loose densities for common US landscape and construction aggregates. Wet stone can weigh 5–10% more; always confirm with your local quarry's scale ticket data.
| Material | Tons / yd³ | Lbs / ft³ | Primary Uses |
|---|---|---|---|
| #57 Crushed Stone | 1.40 | 104 | Driveways, French drains, drainage layers, concrete aggregate |
| Pea Gravel | 1.35 | 100 | Walkways, play areas, dog runs, pipe bedding |
| Crusher Run / Dense Grade (DGA) | 1.60 | 118 | Driveway base, paver & patio sub-base, shed pads |
| Decomposed Granite (DG) | 1.50 | 111 | Pathways, xeriscape, patios, deck footing pads |
| River Rock (1"–3") | 1.30 | 96 | Dry creek beds, edging, downspout splash areas |
Tip: Crusher run is heavier per yard because stone dust fills the voids between particles. Clean, single-size stones like #57 and river rock contain 35–45% air voids.
3. Depth & Compaction Field Guide
Ordering the wrong depth is the #1 cause of rutted driveways and sunken pavers. Use these field-tested minimums as a starting point, and increase depth over clay, wet, or freeze-thaw-prone soils.
Recommended installed depths
2 in
Topdressing & refresh
Top coat over an existing compacted base, decorative mulch replacement, garden beds.
3 in
Walkways & garden paths
Foot traffic only. Pea gravel or DG over landscape fabric with steel or paver edging.
4 in
Light driveways & patio base
Passenger vehicles on firm soil; standard paver sub-base under 1 in of bedding sand.
6–12 in
Heavy equipment & new builds
Trucks, RVs, and construction entrances. Install in 3–4 in lifts: larger base stone (#3 or #4) below, crusher run on top.
Compaction factors: crusher run vs. drainage stone
Loose material delivered by the truck occupies more volume than it will after it's compacted and settled. That's why every serious estimate includes a compaction and waste factor.
-
Crusher run / dense grade: 10–15%. Fines lock together under a plate compactor and the material consolidates significantly. Use 15% on soft or freshly excavated subsoil.
-
#57 stone & drainage aggregate: 5–8%. Clean, angular stone self-locks with minimal settling. The factor mainly covers spillage and uneven trench bottoms.
-
Pea gravel & river rock: 5%. Rounded stone doesn't compact much, but it migrates. Budget a little extra for edges and future topdressing.
-
Decomposed granite: 10–20%. Stabilized DG compacts heavily when wetted and rolled in lifts.
Pro tip from the field
Running short by half a ton means paying a second delivery fee — often $75–$150. Rounding your order up to the next half or whole ton is almost always cheaper than a return trip.
4. Frequently Asked Questions
How many tons of gravel are in a cubic yard?
Most gravel weighs between 1.3 and 1.6 short tons per cubic yard (2,600–3,200 lbs). #57 crushed stone averages about 1.40 tons/yd³, pea gravel 1.35, river rock 1.30, decomposed granite 1.50, and crusher run about 1.60 because its stone dust fills the voids. A safe rule of thumb for budgeting is 1.4 tons per yard.
How much area does a 50 lb bag of pea gravel cover?
A standard 50 lb bag holds roughly 0.5 cubic feet. Coverage depends on depth:
- 1 in deep: ~6 sq ft per bag
- 2 in deep: ~3 sq ft per bag
- 3 in deep: ~2 sq ft per bag
For anything over about 1 cubic yard (54 bags), bulk delivery is usually far cheaper per ton than bagged stone.
What is the difference between #57 stone and Crusher Run?
#57 stone is clean, washed, angular stone sized about 3/4" to 1" with no fines. Water drains straight through it, making it ideal for French drains, behind retaining walls, and as a driveway top layer.
Crusher run (also called dense grade aggregate, DGA, #411, ABC, or road base) is crushed stone blended with stone dust. It compacts into a hard, nearly impervious base — perfect under pavers, patios, and driveways, but poor for drainage.
A common driveway build uses 4–6 in of compacted crusher run topped with 2 in of #57 stone.
How many cubic yards fit in a pickup truck or dump truck?
Weight, not bed size, is the limit. A half-ton pickup should carry no more than about 1 ton (~0.7 yd³) of gravel; a 3/4-ton about 1.5 tons. A tri-axle dump truck typically hauls 15–22 tons depending on state weight limits — this calculator uses a conservative 15 tons per load.