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Bags of Crushed Stone for a 20x10 Patio

How many bags of crushed stone for a 20x10 patio: at 3 inches deep you need about 50.0 cubic feet, which is 100 bags of the common 0.5 cubic foot size. If your store sells crushed stone in 50-pound bags instead, figure about 104 bags, since crushed stone weighs roughly 104 pounds per cubic foot.

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Bag count by depth

DepthCubic feet0.5 cu ft bags50 lb bags (approx.)
1 in16.73435
2 in33.36770
3 in50.0100104
4 in66.7134139

How to figure it

  1. Area: 20 × 10 = 200 sq ft.
  2. Volume: 200 × (3 ÷ 12) = 50.0 cu ft.
  3. Bags: 50.0 ÷ 0.5 = 100 bags (round up).

Bags or bulk?

A cubic yard is 27 cubic feet, so 50.0 cubic feet is 1.85 yards, about 2.6 tons. Past about a yard, bulk is usually less work and often less money. Compare the bag price × 100 against a bulk quote for 2.9 tons delivered.

About crushed stone

Most quarries sell crushed stone by a size number or a screen size. Clean crushed stone drains well; stone with fines packs harder but sheds water more slowly.

Install tips for a patio

  • Dig and level. Remove sod and set the base slightly below the surrounding grade.
  • Edge it. Steel, plastic or stone edging keeps material in place.
  • Spread in layers. Rake to depth, then tamp or wet and compact.
  • Buy a few extra. Grab 5 to 10 percent more bags for settling and touch-ups.

The volume and tonnage calculator handles other sizes and depths.

Where crushed stone fits

Best suited to:

  • Driveway top courses and parking pads
  • Shed and hot tub bases
  • Backfill behind walls when a clean size is used

Think twice for:

  • Barefoot areas, since angular stone is rough
  • Play areas
  • Places that need a smooth rolling surface for wheels

Quick reference numbers

  • Per inch over 100 sq ft: about 0.43 tons of crushed stone (0.31 cubic yards).
  • Per inch over 1,000 sq ft: about 4.3 tons.
  • Another size for comparison: a 20x25 area at 3 inches takes about 6.5 tons.
  • Weight used here: about 1.4 tons per cubic yard.

Common estimating mistakes

  • Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
  • Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
  • Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
  • Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.

Questions people ask

How many bags of crushed stone for a 20x10 patio?

About 100 bags of 0.5 cubic feet at 3 inches deep.

How many 50 lb bags of crushed stone for 20x10?

About 104 bags at 3 inches.

How many 0.5 cubic foot bags are in a cubic yard?

54 bags.

How many cubic feet is a 20x10 patio at 3 inches?

About 50.0 cubic feet.

When does bulk make more sense?

Usually once the job passes about a cubic yard, or when you would need more than a few car trips.

Related guides

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