Gravel calculator
Work out how much gravel you need for a path, driveway or drainage layer from its area and depth, in tonnes and bags.
Result
Gravel required
Bags needed (25kg)
How to use this tool
- Measure the length and width of the area to cover.
- Enter the depth for your project and gravel product. The example depth is not a specification for a path or driveway build-up.
- Read the weight required and the equivalent number of bags.
Assumptions
- Density is assumed at 1.6 tonnes/m³ for this estimate. Actual bulk density varies with aggregate type, grading, moisture and compaction; check supplier data for the selected product.
- Bag count assumes 25kg per bag. Bag mass and bulk delivery quantities are product- and supplier-specific; compare the supplied quantity and delivery terms.
Technical details: what the fields mean
- Length
length - The longest side of the area to cover.
- Width
width - The other side of the area to cover.
- Depth
depth - Chosen layer thickness. A decorative surface and a designed/compacted sub-base are different layers; use project and supplier guidance rather than treating an example depth as a specification.
Methodology
Volume = length × width × depth. Estimated weight = volume × 1.6 tonnes/m³, an illustrative density that varies by aggregate, grading, moisture and compaction. Bag count assumes 25kg per bag.
Worked example
5m × 3m area, 5cm chosen depth
Inputs: Length: 5 m, Width: 3 m, Depth: 5 cm
Result: 0.75m³; about 1.20 tonnes at the calculator's illustrative 1.6t/m³ density, or 48 assumed 25kg bags. Check the selected aggregate density and package mass.
Practical guidance
- For a driveway or heavily used path, use a design appropriate to the ground, intended loads and local conditions; a sub-base and surface layer may be separate materials and depths.
- Compare supplier quotes for bagged, bulk-bag and loose deliveries, checking actual weight, aggregate and delivery terms.
Common mistakes
- Treating this volume-and-weight estimate as a driveway specification; layer design depends on ground and intended use.
- Assuming a universal aggregate density or bag mass instead of checking the selected product label or supplier.
FAQs
How much gravel do I need for a 5m x 3m area?
At a chosen depth of 5cm, the geometric volume is 0.75m³. The calculator estimates about 1.20 tonnes using 1.6t/m³, or 48 assumed 25kg bags; actual density and package mass depend on the product.
How deep should a gravel driveway be?
There is no single depth specified by this calculator. Driveway construction depends on ground conditions, intended loads and materials; get project-specific guidance and enter each relevant layer separately where appropriate.
Last reviewed: 2026-10-11
A simple rectangular-area estimate using an average gravel density — check the exact density for your chosen gravel type for a precise weight.
This tool provides an indicative estimate, based on the assumptions stated above.
Theme and tool preferences, along with saved and recently used lists, are stored only in this browser.