How Much Crushed Stone for a 20×20 Patio?
A 20 × 20 ft patio (400 ft²) at 4″ deep needs 8.9 tons of crushed stone — 4.94 yd³ net plus 20% waste. Order 9.00 t — quarries sell by the ton; a tri-axle carries about 20 tons per load.
20×20 at other depths
| Depth | Volume | Order (tons) | 50 lb bag (0.5 ft³) |
|---|---|---|---|
| 4″ (this page) | 4.94 yd³ | 8.9 tons | 320 |
| 6″ | 7.41 yd³ | 13.3 tons | 480 |
| 8″ | 9.88 yd³ | 17.8 tons | 640 |
Other patio sizes
Order 9.00 t — quarries sell by the ton; a tri-axle carries about 20 tons per load.
- Area
- 400 ft²
- Volume (133.3 ft³)
- 4.94 yd³
- Net weight @ 1.50 t/yd³
- 14,815 lb · 7.41 t
- Waste / settling 20%
- + 1.48 t
- Order quantity
- 8.89 tons
- Truckloads
- 1 × tri-axle dump (≈20 t)
- Metric
- 3.78 m³ · 8.06 tonnes
- 50 lb bag (0.5 ft³)
- 320 bags
- Materials + delivery$20–$50 / ton · Sep 2026
- $265 – $535
- Installed (with labor)typ. $595
- $398 – $891
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What will this crushed stone job cost?
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Different size or depth?
Open the full crushed stone calculator to change every input, pick a material and see truckloads.
How to calculate crushed stone by hand
Tons = Length (ft) × Width (ft) × Compacted depth (in) ÷ 12 ÷ 27 × 1.5 t/yd³ × 1.20 compaction
Worked example
- Area: 16 ft × 12 ft = 192 ft².
- Compacted volume: 192 ft² × (4 in ÷ 12) = 64 ft³ = 2.37 yd³.
- Weight: 2.37 yd³ × 1.5 t/yd³ = 3.56 tons compacted.
- Compaction and waste 20%: 3.56 × 1.20 = 4.27 tons → order 4.5 tons.
- 1 ton ¾″ minus at 4″ compacted
- ≈ 45 ft²
- 1 ton ¾″ minus at 6″ compacted
- ≈ 30 ft²
- Loose-to-compacted
- × 1.15–1.20
- 1 yd³ crusher run
- ≈ 3,000 lb · 1.5 t
Questions crews ask
How much crushed stone do I need for a base?
Multiply area in square feet by compacted depth in inches, divide by 324 for cubic yards, multiply by 1.5 for tons, then add 15–20% for compaction. A 16 × 12 ft patio at 4″ needs about 4.3 tons; order 4.5.
How thick should a crushed stone base be?
4″ compacted under a patio or walkway, 6″ under a driveway, 8–12″ under anything that sees trucks or sits on clay. Compact in 2–3″ lifts with a plate compactor; you cannot compact 6″ in one pass.
What is ¾″ minus, crusher run and 21A?
Different regional names for the same thing: crushed stone from ¾″ down to dust. The fines let it lock together when compacted, which is why it is the base material. Clean stone like #57 has no fines and stays loose — it drains but does not lock.