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Gravel Calculator

Everyday

Calculate how much gravel you need by volume and weight. Enter the area dimensions and depth to get cubic metres and tonnes required for your project.

Reviewed by the thecalcu.com team · Last updated July 30, 2026

0.5200
0.5200
250
1,2002,200

Gravel Needed (tonnes)

1.8
Volume
1.125
Weight (kg)
1,800

This calculator computes your Gravel Needed (tonnes), Volume, Weight (kg) from the values you enter.

Inputs
LengthWidthDepthGravel Density
Outputs
Gravel Needed (tonnes)VolumeWeight (kg)

What is a Gravel?

A Gravel Calculator works out how much gravel you need for a path, driveway, or landscaping project, based on the area you're covering and how deep a layer you want. Gravel is sold by weight in bulk quantities, but most people think about their project in terms of area and a desired layer thickness, this calculator bridges that gap, converting your measurements into both volume and weight.

This calculator handles the area-to-weight conversion using gravel's typical bulk density, with an adjustable density input for different gravel types. It pairs well with the Concrete Calculator and Square Footage Calculator for related material and area estimates.

Why Use a Gravel Calculator?

Ordering the wrong amount of gravel is an expensive mistake in either direction, running short means an inconvenient extra delivery, often with a minimum order fee, while over-ordering means paying for material you don't need and then dealing with disposal or storage. Because gravel is sold by weight but used by volume, getting from "I want a 5m × 3m path, 7.5cm deep" to "I need 1.8 tonnes" requires a density conversion most people don't have memorised.

This calculator handles that conversion instantly. Someone planning a driveway resurfacing project, or a landscaper quoting multiple jobs, can get an accurate tonnage estimate in seconds rather than guessing or searching for a density conversion factor separately.

Who Should Use This Calculator?

  • Homeowners planning a driveway, path, or garden gravel project who need to know how much to order.
  • Landscapers and contractors quoting material costs for gravel-based projects.
  • Builders estimating gravel needed for drainage layers, soakaways, or sub-base preparation.
  • DIY enthusiasts comparing gravel costs across suppliers who quote in different units (weight vs. volume).
  • Anyone budgeting a landscaping project who needs an accurate material estimate before getting supplier quotes.

What Insights Does the Gravel Calculator Give You?

The calculator returns three related figures covering both ways gravel is commonly measured and sold:

  • Gravel Needed (tonnes), the headline figure, matching how most bulk suppliers quote and deliver gravel.
  • Volume, the total cubic metres of gravel needed, useful for comparing against bagged product volumes.
  • Weight (kg), the same weight figure in kilograms, useful for matching against bagged gravel weights at hardware stores.

Having all three figures means you can work with whichever unit your specific supplier uses, without needing to do a manual conversion yourself.

How to use this Gravel calculator

  1. Measure the Length and Width of the area you're covering, in metres.
  2. Set the Depth you want the gravel layer to be, in centimetres, typically 5cm for paths, 7.5–10cm for driveways.
  3. Adjust the Gravel Density if your supplier specifies a different value than the default 1,600 kg/m³.
  4. Read the Gravel Needed (tonnes) result for the amount to order from a bulk supplier.
  5. Check Volume and Weight (kg) if you're comparing against bagged product sizes instead.
  6. Consider adding 5–10% extra to the result to account for settling and uneven ground.
Show formula & methodology ↓Show less ↑

Formula & Methodology

The calculator first computes volume, then converts to weight using density:

Volume (m³) = Length × Width × Depth (converted to metres)
Weight (kg) = Volume × Density
Weight (tonnes) = Weight (kg) ÷ 1000

Worked example: for a 5m × 3m area with a 7.5 cm depth and standard 1,600 kg/m³ density:
- Volume = 5 × 3 × 0.075 = 1.125 m³
- Weight = 1.125 × 1,600 = 1,800 kg
- Weight in tonnes = 1,800 ÷ 1,000 = 1.8 tonnes

Frequently Asked Questions

How much gravel do I need for my driveway or path?
The amount depends on the area you're covering and how deep a layer you want, multiply length × width × depth to get volume, then multiply by gravel's density to get weight. A typical driveway layer of 7.5 cm depth over a 5m × 3m area needs roughly 1.8 tonnes of standard gravel.
What is a typical depth for a gravel path or driveway?
Footpaths typically use a 5 cm gravel depth, while driveways that need to support vehicle weight usually use 7.5–10 cm, sometimes with a compacted sub-base layer underneath. Deeper applications like soakaways or drainage layers may need significantly more.
What is the typical density of gravel?
Standard gravel typically has a bulk density of around 1,600–1,700 kg per cubic metre, though this varies by stone type and size, denser materials like crushed stone can reach 1,800–2,000 kg/m³, while lighter decorative gravel may be less. Check with your supplier for the specific material's density if precision matters.
Why does the calculator ask for depth in centimetres but length and width in metres?
Gravel layers are typically much shallower than the length and width of the area being covered, so centimetres give a more intuitive and precise way to enter a thin depth (like 5–10 cm) compared to working in fractional metres. The calculator converts everything to consistent units internally.
Should I order extra gravel beyond the calculated amount?
Many suppliers and contractors recommend ordering 5–10% extra to account for settling, uneven ground, and minor spillage during delivery and spreading. This is especially worth doing for larger projects where running short means an inconvenient second delivery.
How is gravel sold, by weight or volume?
Gravel is most commonly sold by weight (tonnes or kg) by bulk suppliers, though smaller bagged quantities at hardware stores are often sold by volume (litres or cubic feet). This calculator gives both volume and weight so you can match whichever unit your supplier uses.
Does gravel type affect how much I need?
Yes, different gravel types have different densities, so the same volume of two different materials can weigh noticeably different amounts. Adjust the Gravel Density input if your supplier specifies a density different from the default, to get an accurate weight estimate.
What's the difference between this and the Concrete Calculator?
The [Concrete Calculator](/concrete-calculator/) estimates material quantities for mixed concrete (cement, sand, aggregate), while this Gravel Calculator estimates loose gravel for paths, driveways, or drainage layers that aren't being mixed into concrete. Both work from similar area × depth volume logic but apply to different materials.
Can I use this calculator for a garden bed or landscaping project?
Yes, the same volume and weight calculation applies whether you're covering a driveway, footpath, garden bed, or any other area with a gravel layer. Just adjust the depth to match what's appropriate for your specific landscaping use.
How do I convert the result into the number of bags I need to buy?
Check the weight printed on your gravel bags (commonly 20–25 kg per bag) and divide the calculator's Weight (kg) result by that figure to get the number of bags needed. For bulk deliveries, suppliers typically quote and deliver by the tonne directly.
Also known as
how much gravel do I needgravel volume calculatorgravel tonnage calculatordriveway gravel calculatorgravel weight estimator