Gravel Calculator

Last updated: Jul 22, 2026 | Reviewed by Calkulator Team | 2 min read

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Compute gravel volume and weight for driveways and landscaping

A 5m × 3m driveway at 10cm depth needs 1.5 cubic metres of gravel — approximately 2.4 tonnes. Different gravel types (pea, crushed, limestone) have different densities affecting the weight and number of bags to order.

Compact gravel settles about 15-20% — order extra to account for settling after a few rain cycles.

Length (m)

Width (m)

Depth (cm)

Recommended: paths 5–10 cm, driveways 10–15 cm

Gravel Type

Materials Needed

Volume

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Weight

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Bags Needed

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Live Result Illustration

Visual summary — updates instantly as you enter values above

LIVE

Real-Life Guide to Using the Gravel Calculator

Gravel volume for paths and beds. Use the examples and checks below to turn the number into a practical decision.

When this calculator is useful

Handy when laying a garden path, driveway base, or landscaping bed and you need to know how many tonnes or cubic feet of gravel to order so the delivery truck brings the right quantity in one trip.

For most people, the best way to use the Gravel Calculator is to try the real case first, then change one input at a time. That makes the trade-off visible. For example, with a loan calculator you can change tenure while keeping the same rate; with an investment calculator you can change return assumption while keeping the same monthly contribution; with a health, education or measurement calculator you can check how much one input changes the final category.

The result should answer a practical question: Can I afford this? How much should I save? Is this score enough? Is this measurement within range? What is the safer or cheaper option? If the output does not answer the decision clearly, adjust the inputs until the scenario matches your real situation.

Real-Life Example

Laying a garden path: A homeowner in Bengaluru wants to lay a 40 ft long, 3 ft wide gravel path with a compacted depth of 3 inches (0.25 ft).

1Volume = 40 x 3 x 0.25 = 30 cu ft. Converting to cubic yards: 30 / 27 ≈ 1.11 cu yd. Using an average density of about 1.4 tonnes per cubic yard for crushed stone, that comes to roughly 1.55 tonnes, which most suppliers would round up to a 1.5-2 tonne delivery load.

2Now change one input, such as rate, time, quantity, unit or score, and compare the new result with the first one.

Small paths often need less than a full tonne of gravel, so check your supplier's minimum order quantity before finalising the delivery, since many charge extra for partial-tonne deliveries.

Practical Advice

Use the Gravel Calculator as a planning tool, not just a number generator. Write down the inputs you used, because the final answer is meaningful only when you remember the assumptions behind it.

If the decision affects money, health, tax, safety, academics or legal compliance, keep a second check ready. That second check may be a bank quote, payslip, official rule, prescription, site measurement, mark sheet or invoice.

Common Mistakes

Calculating area only and forgetting to multiply by depth, which is the single biggest source of under-ordering gravel.
Using a shallow 1-inch depth figure meant for decorative topping when the path actually needs a 3-4 inch compacted base layer.
Not accounting for compaction — loose gravel settles by roughly 15-20% once compacted, so you need more loose volume than the finished depth suggests.
Mixing up cubic feet and cubic yards when talking to a supplier who quotes by the tonne, leading to ordering errors of several multiples.
Ignoring that gravel density varies by type — pea gravel, crushed stone, and river gravel don't weigh the same per cubic foot, so a generic conversion factor can be off by 10-15%.

How to Interpret Results

The output gives volume in cubic feet (or cubic yards) and an approximate weight in tonnes using a standard density — treat the weight figure as an estimate and confirm the exact conversion factor with your specific gravel supplier since density varies by stone type and moisture content.

A good interpretation looks at both the main result and the supporting values. If a page shows totals, ratios, categories, schedules or warnings, read those together instead of focusing only on the biggest number.

Gravel Calculator FAQs

Useful answers for interpreting the output, avoiding mistakes and using the result responsibly.

What does the Gravel Calculator work out for me?

It multiplies the length, width, and depth of the area you want to cover to get a volume in cubic feet, then converts that volume into an estimated weight in tonnes using a typical gravel density, so you know both how much space it fills and roughly how much to order by weight.

Why does the calculator ask for depth separately from area?

Gravel is bought and priced by volume or weight, not by surface area alone, so a 100 sq ft path at 2 inches deep needs half the material of the same path at 4 inches deep — depth is often the number people forget to adjust for their specific use case.

Should I use the loose volume or the compacted volume?

Enter the finished, compacted depth you want (for example, 3 inches for a path base), and add roughly 15-20% extra volume when ordering loose gravel, since it settles once spread and compacted with a plate compactor or by foot traffic.

The supplier's tonnage quote doesn't match my calculation — why?

Gravel density varies by material type — pea gravel, crushed granite, and river stone all weigh differently per cubic foot — so ask your supplier which density figure they use and adjust the calculator's weight estimate accordingly, or treat the calculator's cubic footage as the more reliable number.

What depth should I use for a driveway versus a decorative path?

A vehicle driveway typically needs a 4-6 inch compacted gravel base for load-bearing strength, while a decorative garden path or flower bed topping usually only needs 1-2 inches, so match your depth entry to the actual use case.

How do I handle an irregularly shaped bed, like a curved border?

Break the curved area into several smaller rectangles or triangles that approximate the shape, calculate each section's volume separately, and add them together for a reasonably accurate total.

Does this calculator account for a sub-base layer under the gravel?

No, if your project needs a separate sub-base of larger crushed stone beneath a finishing layer of smaller gravel, run the calculator twice — once for each layer's depth and material — and order them separately.

How much extra should I add for delivery buffer?

A 10% buffer on top of the calculated volume is a reasonable safety margin for spillage and uneven spreading, but check if your supplier allows partial-tonne top-ups later, since it's often cheaper to slightly under-order and reorder a small amount than to have excess gravel left over.

How to Calculate Gravel

Gravel quantity is calculated by volume (length × width × depth) then converted to weight using the material's bulk density. Dry gravel is about 1,680 kg/m³; wet or compacted gravel is closer to 2,000 kg/m³. For garden paths, 5–10 cm depth is typical; driveways need 10–15 cm.

Order slightly more than calculated to account for compaction and settling — typically add 10–15% extra. Gravel is often sold in bulk (per tonne) or in 25 kg or 50 kg bags for smaller quantities.

Example

10m × 3m path, 8 cm deep:

1Volume: 10 × 3 × 0.08 = 2.4 m³

2Weight: 2.4 × 1,680 = 4,032 kg

✓ ~4 tonnes, or 162 × 25 kg bags

Frequently Asked Questions

How much gravel do I need per square metre?

For a 50 mm (2-inch) deep layer, you need 0.05 m³ per m². A 10 m × 5 m driveway with a 50 mm layer requires 10 × 5 × 0.05 = 2.5 m³. Add 10–15% for wastage and compaction. Loose gravel compacts by about 15–20% when settled, so always order slightly more than calculated.

What size gravel is best for driveways?

20–25 mm (¾ inch) gravel is ideal for driveways — small enough to bind together, large enough to resist displacement under tyres. For pathways, use 10–14 mm pea gravel. For drainage layers under slabs, use 20–40 mm crushed stone. Avoid very fine gravel (less than 6 mm) for driveways as it scatters easily.

How heavy is gravel per cubic metre?

Gravel density is typically 1,600–1,700 kg/m³ (1.6–1.7 tonnes per m³). A standard truck carries 6–8 tonnes, which equals roughly 4–5 m³ of gravel. For small quantities, a 50 kg bag covers approximately 0.03 m³ at 50 mm depth. Use these figures to estimate delivery quantities and costs.