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Gravel Calculator

Cubic yards and tons of gravel for a driveway, path or pad — with the density assumption shown, not hidden.

Enter the area and depth to see cubic yards and tons.

Area shape

The depth you want once it is spread and compacted. 3–4 inches per layer is typical for a driveway.

Material

This is what turns volume into tons. There is no universal figure — if your supplier quotes a density or a tons-per-yard number, use theirs.

Extra volume for settling

Spillage and uneven ground

Cost (optional)

Estimate. A real-world figure based on the assumptions listed below, which you can change.

How this calculator works

Volume is straightforward: area times depth, converted to cubic yards at the exact 27 cubic feet per yard. Tonnage is where honesty matters.

**There is no universal cubic-yard-to-ton conversion for aggregate.** Density varies with the rock type, the gradation, how much fine material is mixed in and how wet the pile is. A dense crusher run and a dry pea gravel can differ by 20% or more. Any calculator that prints a fixed tons-per-yard figure without telling you the density is guessing on your behalf.

So density is a visible, editable field here, pre-filled with a typical value for the material you pick. If your supplier quotes a density or a tons-per-yard figure, use theirs — they know what is in their pile.

Compaction and waste are handled separately because they are different things. Compaction accounts for aggregate losing volume when it is rolled; a driveway base finished at four inches needs materially more than four inches of loose stone. Waste covers spillage, uneven sub-grade and over-ordering at the edges.

The formula

Exactly what happens to your numbers, step by step.

  1. Volume

    cubic feet = area (sq ft) × depth (inches) ÷ 12
cubic yards = cubic feet ÷ 27

  2. What to order

    order volume = cubic feet × (1 + compaction %) × (1 + waste %)

  3. Tonnage

    tons = order volume (ft³) × density (lb/ft³) ÷ 2,000

    The density figure is the entire basis of this number. Change it and the tonnage changes proportionally.

A worked example

A 40 × 12 foot driveway, 4 inches of crushed stone, with 10% compaction and 5% waste.

What you enter

Area
40 ft × 12 ft = 480 sq ft
Depth
4 inches
Material
Crushed stone at 100 lb/ft³
Compaction
10%
Waste
5%

The working

Finished volume
480 × 4 ÷ 12 = 160 ft³
In cubic yards
160 ÷ 27 = 5.93 yd³
With compaction and waste
160 × 1.10 × 1.05 = 184.8 ft³
Order volume
6.84 yd³
Weight
184.8 × 100 ÷ 2,000 = 9.24 tons

Order about 6.8 cubic yards, or 9.2 tons

At a different density — say 115 lb/ft³ for crusher run — the same volume is 10.6 tons. That is a 15% difference in what you pay if you buy by weight, which is why the density field matters.

Assumptions

Every result here rests on these. Change your inputs and the result changes with them.

  • The depth entered is the finished, compacted depth you want.
  • Density values are typical loose dry figures for ordering purposes, not specifications. Wet material weighs more.
  • The area is flat and reasonably level. Slopes and hollows change the volume.
  • Cost figures cover material only. Delivery, spreading and compaction are normally charged separately.

What this cannot tell you

  • It cannot tell you what depth your project needs. A footpath, a parking pad and a driveway carrying trucks have very different requirements.
  • It does not account for a geotextile fabric, edging or a sub-base layer.
  • Suppliers sell in their own increments; you may not be able to order exactly this quantity.

Questions people ask

How many tons is a cubic yard of gravel?

Between about 1.2 and 1.6, depending entirely on the material. At 100 lb per cubic foot it is 1.35 tons; at 115 lb it is 1.55. This is why the density field exists rather than a fixed conversion — ask your supplier for their figure.

How deep should a gravel driveway be?

Typically 4 to 6 inches for a residential driveway, often built in layers with a coarser base beneath a finer top. A footpath can be 2 to 3 inches. Ground conditions and the traffic it will carry both matter.

Why do I need a compaction allowance?

Because aggregate loses volume when it is rolled. Spread four inches loose and compact it and you end up with noticeably less than four inches, so you need more material than the finished depth implies.

Should I buy by the yard or by the ton?

Whichever your supplier quotes. The figures here are shown both ways from the same volume, so you can compare two quotes on the same basis.

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Sources and review

This calculator uses standard arithmetic with no external rules or published rates, so there is nothing to cite beyond the formulas shown above.

Methodology version 1.0.0 · Last reviewed