Gravel Driveway Calculator

Calculate driveway gravel by section and by layer, with optional compaction, extra material and per-layer density for an estimated weight.

Gravel driveway calculator

Units
Project sections

Add each part of the driveway. Section areas are added together.

Driveway section 1

Shape

For a square, enter the same length and width.

Calculation mode

One layer stack applies to all sections. If parts of the project need different layers, calculate them separately.

Layers

Layer 1

For example Sub-base, Base or Surface. Names are labels only.

Groups totals by material. It does not supply a density.

Enter the finished depth for this layer. No default depth is supplied.

Layer densityOptional — needed only for this layer’s estimated weight

Use the figure your supplier gives for this exact product.

Where can I find bulk density?

Ask your quarry, landscape supplier, aggregate supplier or delivery company for the product's bulk density, unit weight, or tons-per-cubic-yard figure.

  • Ask for the loose bulk density if you are ordering loose delivered material.
  • Confirm whether the figure is loose delivered, compacted/in-place, or another condition.
  • Confirm whether “tons” means US short tons or metric tonnes.
Compaction / yieldOptional — only if your supplier or project gives a figure
How do you know the adjustment?

Specifications such as “95% maximum dry density” are density-test targets. They do not mean adding 5% more material.

Applied to this layer after any compaction adjustment. It is separate from compaction.

Result

Your result will appear here

Enter your driveway measurements to see quantities by layer.

How this calculator works

The driveway calculator works in three steps:

  1. Sections set the area. Each section's area is calculated, then all sections are added together.
  2. Layers set the depths. One layer stack applies to the whole project area. Each layer's finished volume is the total area × that layer's finished depth.
  3. Optional adjustments are applied per layer. Compaction or yield first, then any Extra material / handling allowance.

Loose volume = Finished volume ÷ (1 − volume reduction)

Loose volume = Finished volume ÷ loose-to-compacted yield

Order volume = Loose volume × (1 + allowance)

Use one compaction method per layer, and only with a figure from your supplier or project. Weight is calculated only for layers where you enter a bulk density. Totals are grouped by material.

Planning driveway layers

There is no universal driveway depth

How thick each layer should be depends on traffic, the ground underneath, drainage and climate. This calculator does not recommend depths. Enter the depths from your plan, contractor or local guidance.

FHWA's gravel-road guide shows why: its layer thicknesses change with heavy-truck traffic and subgrade support, and they were written for reconstructed rural gravel roads, not private driveways. FHWA's unpaved-road guidance for wearing courses applies to treated unpaved roads, not residential driveways.

Compaction and extra material are separate

Compaction accounts for material packing down when it is compacted. The Extra material / handling allowance covers waste, handling or contingency. The calculator applies compaction first, then the allowance. Neither is added unless you enter it. A specification such as “95% maximum dry density” is a density-test target — it does not mean adding 5% more material.

Topping up an existing driveway

For a top-up, measure the depth you are actually missing and enter that as the finished depth. Do not use the full original layer thickness.

Different structures in different areas

All sections share one layer stack. If part of the project needs a different structure — a heavier parking pad, for example — calculate that part separately.

Limitations

This calculator estimates quantities. It does not design a driveway structure or check drainage or load capacity. If you are unsure about depths or ground conditions, get a professional assessment.

Need one area of loose material without layers? Use the Gravel Calculator. To price the result, use the Gravel Cost Calculator.

Worked example

Example: two sections, base and surface layers

  1. Sections: 60 ft × 12 ft = 720 ft² and 20 ft × 18 ft = 360 ft², total 1,080 ft²
  2. Base, 4 in finished: 1,080 × 0.3333 = 360 ft³ = 13.33 yd³
  3. Base with a 20% volume reduction from the supplier: 13.33 ÷ 0.80 = 16.67 yd³ loose
  4. Base with a 5% allowance: 16.67 × 1.05 = 17.50 yd³
  5. Surface, 2 in finished: 1,080 × 0.1667 = 180 ft³ = 6.67 yd³; with 5%: 7.00 yd³

Result: 24.50 cubic yards to order. The depths, reduction and allowance are example inputs, not recommendations.

Frequently asked questions

How deep should a gravel driveway be?

That depends on your soil, drainage, climate and traffic, so this calculator does not set a depth. Use the depths from your plan or contractor, or get a professional assessment if you are unsure.

Why can’t each section have different layers?

In this version, one layer stack applies to all sections. If part of your project needs a different structure, calculate that part separately.

How do I account for compaction?

Open Compaction / yield on a layer and enter a volume reduction or loose-to-compacted yield from your supplier or project. Density-test targets such as “95% maximum dry density” do not mean adding 5% more material.

Why do some layers show no weight?

Weight is calculated only for layers where you enter a bulk density. Without one, you still get that layer’s volume.

How many US short tons of gravel do I need for my driveway?

Enter each layer’s bulk density from your supplier. The result then shows an estimated weight for each layer in US short tons and metric tonnes, and totals by material.

Sources & methodology

Layer quantities are geometry, unit conversion and the adjustments you enter. No external source supplies a driveway depth, compaction factor or density. Sources relevant to this page: