How Much Crushed Stone Under a 16x20 Deck?
A 16 by 20 foot deck covers 320 square feet. At 3 inches of crushed stone, plan on 2.96 cubic yards, or about 4.1 tons, which answers how much crushed stone under a 16x20 deck.
Volume and tonnage calculator →The math
- Area: 320.0 sq ft.
- Depth in feet: 3 ÷ 12 = 0.250 ft.
- Cubic yards: 320.0 × 0.250 ÷ 27 = 2.96 yd³.
- Tons: × about 1.4 tons per yard = 4.1 tons.
The crushed stone calculator does this for any size.
Related: How Much Pea Gravel Under a 16x20 Deck?
Crushed stone needed by depth
| Depth | Cubic yards | Tons of crushed stone | Tons +10% |
|---|---|---|---|
| 2 in | 1.98 | 2.8 | 3.0 |
| 3 in | 2.96 | 4.1 | 4.6 |
| 4 in | 3.95 | 5.5 | 6.1 |
| 6 in | 5.93 | 8.3 | 9.1 |
Stone for a deck
Under a deck, stone is a weed and moisture barrier rather than a structural layer. Slope the soil away from the house, lay fabric and spread 2 to 3 inches of washed stone that drains quickly.
Related: How Much #57 Stone Under a 16x20 Deck?
Prep
Remove sod and roots, level the area and slope it slightly for drainage. Install edging so the stone stays inside the footprint.
Ordering and delivery
If you haul it yourself, a typical half-ton pickup should carry only about half a cubic yard of stone, well under what the bed looks like it can hold. Crushed stone has angular faces that lock together under a compactor, which is why it holds a pad shape. Ask your supplier for their own tons-per-yard number, since stone source and moisture change it.
Planning the cost
Stone is usually priced per ton or per cubic yard, and delivery is often a separate charge based on distance. A full truckload can cost less per ton than a partial one, so it can pay to combine projects. Ask whether the quote includes tax, delivery and any small-load fee before you compare yards.
Measuring the area
Measure length and width in feet at a few points and use the largest figures, since real sites are rarely square. For odd shapes, split the area into rectangles and circles, work out each one and add them together. Depth is the number most people underestimate: drive a stake, run a level string and measure down to the dug-out surface in several spots.
Questions people ask
How many tons of crushed stone under a 16x20 deck?
About 4.1 tons at 3 inches deep.
How many yards of crushed stone under a 16x20 deck?
About 2.96 cubic yards.
How many tons of crushed stone are in a cubic yard?
Roughly 1.4 tons for planning, but suppliers vary with stone size and moisture.
Should I put landscape fabric under the stone?
On soft or clay soil, a woven geotextile keeps stone from sinking into the dirt and makes the layer last longer.
Related guides
- Gravel Under a Deck: Weeds, Drainage, and Depth
- How Much Does a Ton of Gravel Cover? Depth Chart
- Tons to Cubic Yards for Gravel: Conversion Chart
- Crushed Stone vs Gravel: Differences and Best Uses
- Geotextile Fabric for Driveways: Woven vs Nonwoven and How Much You Need
- Compacting a Driveway Gravel Base in Lifts
- How Much Pea Gravel Under a 16x16 Deck?
- How Much Gravel Under a 16x20 Deck?
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