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How Much Crushed Stone for a 12x70 Driveway?

A 12 by 70 foot driveway is 840 square feet. How much crushed stone for a 12x70 driveway depends on depth: at 4 inches it is about 10.37 cubic yards or 14.5 tons. Suppliers usually sell by the ton, so the tonnage is the number to give them.

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The math for a 12x70 driveway

  1. Area: 12 × 70 = 840 sq ft.
  2. Depth in feet: 4 ÷ 12 = 0.333 ft.
  3. Cubic feet: 840 × 0.333 = 280.0 cu ft.
  4. Cubic yards: ÷ 27 = 10.37 yd³.
  5. Tons: × 1.4 = 14.5 tons.

The volume and tonnage calculator does this for any size.

Crushed stone needed by depth

DepthCubic yardsTons (approx.)Tons +10%
2 in5.197.38.0
3 in7.7810.912.0
4 in10.3714.516.0
6 in15.5621.824.0

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. If the yard sells by the cubic yard instead of the ton, use the cubic-yard column directly.

Preparing the driveway

Strip sod and soft topsoil, grade for drainage and compact the subgrade before any stone goes down. Gravel drives last longer with a compacted base layer under the top stone and a slight crown so water runs off. This driveway sees car and truck traffic, 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. 16.0 tons may take more than one 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 driveway as firm ground allows.

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

Poor fit 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 10x20 area at 4 inches takes about 3.5 tons.
  • Weight used here: about 1.4 tons per cubic yard.

Common estimating mistakes

  • Mixing up cubic yards and tons. Yards are volume, tons are weight; convert with the product’s weight per yard.
  • Ignoring the base. A thin surface layer over soft soil fails early no matter how much material is on top.
  • Ordering exactly the math. Uneven ground and spillage nearly always need a little more than the flat calculation.
  • Using inches as if they were feet. Depth has to be divided by 12 before you multiply; skipping that step inflates the order twelvefold.

Questions people ask

How many tons of crushed stone for a 12x70 driveway?

About 14.5 tons at 4 inches deep, or 16.0 tons with 10 percent extra.

How many cubic yards is a 12x70 driveway at 4 inches?

About 10.37 cubic yards.

How much does a cubic yard of crushed stone weigh?

Usually around 1.35 to 1.5 tons, depending on stone size, fines and moisture.

How deep should crushed stone be for a driveway?

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 12x70?

840 square feet.

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