AsphaltTons.com — asphalt tonnage calculator

How Much Gravel for a 12x18 Patio?

How much gravel for a 12x18 patio is a quick volume problem. 216 square feet at 3 inches comes to 2.00 cubic yards. Gravel usually weighs about 1.3 to 1.5 tons per cubic yard, so plan on roughly 2.8 tons.

Volume and tonnage calculator →

The math for a 12x18 patio

  1. Area: 12 × 18 = 216 sq ft.
  2. Depth in feet: 3 ÷ 12 = 0.250 ft.
  3. Cubic feet: 216 × 0.250 = 54.0 cu ft.
  4. Cubic yards: ÷ 27 = 2.00 yd³.
  5. Tons: × 1.4 = 2.8 tons.

The volume and tonnage calculator does this for any size.

Gravel needed by depth

DepthCubic yardsTons (approx.)Tons +10%
2 in1.331.92.1
3 in2.002.83.1
4 in2.673.74.1
6 in4.005.66.2

About gravel

Because ’gravel’ covers so many products, the weight per yard moves with stone size and how much fine material is in the pile. Rounded stone with no fines rolls under tires; crushed stone with fines locks together. Weight per yard is a planning number; the scale ticket at the yard is the real one.

Preparing the patio

Remove sod, level the area with a slight slope away from the house, and lay landscape fabric if weeds are a concern. Edging keeps loose material inside the patio footprint. This patio sees foot traffic and furniture, so match the depth to that load rather than to the minimum.

Ordering tips

  • Round up. Compaction and uneven ground eat material. Adding about 10 percent is common.
  • Delivery size. 3.1 tons fits in a single typical dump truck load; small loads may carry a delivery fee. See how many tons of gravel in a dump truck.
  • Bulk vs bags. At this size bulk delivery is usually the practical choice.
  • Where it drops. Have the truck dump as close to the patio as firm ground allows.

Where gravel fits

Good uses:

  • Rural driveways and lanes where low upfront cost matters
  • Drainage areas and around downspouts
  • Temporary access while a site is under construction

Think twice for:

  • Steep slopes, where loose stone washes downhill
  • Spots plowed often, since plows push gravel into the lawn
  • Areas next to doors, because stone tracks inside

Quick reference numbers

  • Per inch over 100 sq ft: about 0.43 tons of gravel (0.31 cubic yards).
  • Per inch over 1,000 sq ft: about 4.3 tons.
  • Another size for comparison: a 10x20 area at 2 inches takes about 1.7 tons.
  • Weight used here: about 1.4 tons per cubic yard.

Mistakes that throw off the order

  • Assuming every supplier uses the same weight. Two yards selling the same product name can quote different tons per yard.
  • Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.
  • Skipping drainage. Water sitting under any surface softens the base and leads to ruts and potholes.
  • Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.

Questions people ask

How many tons of gravel for a 12x18 patio?

About 2.8 tons at 3 inches deep, or 3.1 tons with 10 percent extra.

How many cubic yards is a 12x18 patio at 3 inches?

About 2.00 cubic yards.

How much does a cubic yard of gravel weigh?

Usually around 1.3 to 1.5 tons, depending on stone size, fines and moisture.

How deep should gravel be for a patio?

The table above shows 2 to 6 inches. Shallower depths suit top dressing; deeper depths suit new installs and heavier use.

How many square feet is 12x18?

216 square feet.

Related guides

Open the volume and tonnage calculator → Asphalt tonnage calculator →

As an Amazon Associate, AsphaltTons.com earns from qualifying purchases. Product links below are sponsored.