Gravel Driveway Calculator

Cost = quantity × unit price, where the quantity is the tonnage or the volume, whichever your price is quoted per

L

Length of the driveway, in feet

W

Width of the driveway, in feet

D

Depth of the stone layer, in inches

ρ

Bulk density of the stone, in kilograms per cubic metre

p

The price you were quoted, per ton, per tonne or per yard

Use it to compare quotes from two yards, to check an invoice, or to decide whether the extra depth is worth the extra load. The stone is the cheap part of a driveway: stripping the topsoil, the geotextile, the grading and the delivery are separate lines, and on a soft site they are usually the larger half of the bill.

1. A 40 ft by 12 ft driveway, four inches of crushed stone at 45 a short ton

   1. Area: 40 × 12 = 480 square feet
   2. Depth in feet: 4 ÷ 12 = 0.3333 ft
   3. Volume: 480 × 0.3333 = 160 cubic feet = 160 ÷ 27 = 5.93 cubic yards
   4. Crushed stone at 1,600 kg per m³ is 99.885 lb per ft³: 160 × 99.885 = 15,981.6 lb
   5. 15,981.6 ÷ 2,000 = 7.9908 short tons
   6. The quote is per short ton, so: 7.9908 × 45 = 359.59

   The total is a plain number in whatever currency you priced in — no conversion happens anywhere on this page. That is deliberate: a driver buying stone in one country does not want the page deciding which dollar they meant.

2. A 30 ft by 10 ft path, two inches of pea gravel at 38 a cubic yard

   1. Area: 30 × 10 = 300 square feet
   2. Depth in feet: 2 ÷ 12 = 0.1667 ft
   3. Volume: 300 × 0.1667 = 50 cubic feet = 1.8519 cubic yards
   4. Pea gravel at 1,540 kg per m³ is 96.14 lb per ft³: 50 × 96.14 = 4,807 lb = 2.40 short tons
   5. The quote is per cubic yard, so the volume is the quantity that matters: 1.8519 × 38 = 70.37

   Note which number the price is quoted per. This same load is 2.40 short tons and 1.85 cubic yards; at 38 a yard it costs 70, and at 38 a ton it would cost 91. Prices per ton and per yard are not interchangeable, which is the entire reason the unit is a field rather than a constant.

The density is a typical figure for loose, dry stone — about 1,600 kg per m³ for crushed stone, 1,540 for pea gravel and 1,500 for river rock — and a real load varies with the quarry, the gradation, the moisture and how much the stone has settled in the truck. A wet or compacted load can run 10% heavier, which moves the tonnage and therefore the cost. The depth is the finished, compacted depth: stone spread four inches loose settles below four once it is rolled, so order for the layer you want to end up with. The area is a rectangle, and a curved or tapering drive takes less than the full rectangle. And the total is the stone only — delivery, the geotextile, the machine time to strip and grade the sub-base and any minimum-load charge are separate, and on a soft site they are usually the bigger half.

How much does a gravel driveway cost?

Stone for a 40 ft by 12 ft driveway four inches deep is about 8 short tons, or 5.93 cubic yards, which at 45 a short ton is 360. That is the stone alone: delivery, grading, a geotextile membrane and the machine time are separate lines, and on soft ground they usually cost more than the stone does.

How deep should a gravel driveway be?

Four inches of crushed stone over firm, prepared ground is the usual surface, with six to eight inches where the ground is soft or wet — often over a layer of larger stone to spread the load. The test is that the stone is deeper than the deepest rut it has to bridge; a thin layer over soft ground disappears into it.

Should I price gravel by the ton or by the cubic yard?

Whichever the yard quotes in, and enter it in that unit — the calculator converts. The two are not interchangeable: the same load is 7.99 short tons or 5.93 cubic yards, so a price of 45 a ton is about 60 a yard for crushed stone. Comparing a per-ton quote with a per-yard one without converting is where the 30% surprises come from.

How accurate is the density figure?

It is a typical value, good to about 10% either way — crushed stone runs near 1,600 kg per m³, pea gravel 1,540 and river rock 1,500. Moisture and settlement move it more than the stone type does, so treat the tonnage as the load you will be invoiced for and check the delivery ticket against it.

Do I need to order extra for compaction?

Yes, 10% to 20% over the calculated volume, and more for a deep loose fill. Stone is sold loose and the layer left after rolling is thinner than the layer spread. A short load means a second delivery, and the delivery charge usually costs more than the extra stone would have.

Does the total include tax and delivery?

No. The total is the quantity times the unit price you entered, nothing else. Delivery is often charged per load or per ton with a minimum, tax depends on where you are, and neither is something this page can know. Add them to the figure before you compare it with the quote.

• Approximate Conversions from U.S. Customary Measures to Metric — the chart behind the short ton, cubic yard and pound-per-cubic-foot figures used here — National Institute of Standards and Technology
• The International System of Units (SI) brochure — the kilogram, the metre and the tonne, the three units the density in this calculation is defined in — Bureau International des Poids et Mesures (BIPM)