Gravel by project
How much gravel for a 20 m2 driveway?
A driveway top-layer example using 20 m2 area, 5 cm depth, and a typical decorative gravel density.
Estimated result
Pre-calculated from the example inputs below. Adjust them in the calculator for your own numbers.
- Volume
- 1 m3 (1.31 yd3)
- Weight
- 1.76 t (1.94 US tons)
- Bag count
- 88 x 20 kg bags
A 20 m2 driveway top layer at 5 cm finished depth needs the volume, tonnes, and bag count shown below. This estimate covers the visible gravel layer only. It does not replace sub-base, drainage, or compaction guidance for a load-bearing driveway.
How to use this project example
This example uses a 20 m2 finished area at 5 cm depth. It estimates 1 m3 before applying density and allowance, so it is best used as a quantity check after the finished area and depth are decided.
- Measure inside the edging line or finished border, not the rough excavation area.
- Keep sub-base, compaction, and drainage decisions separate from decorative gravel coverage.
- Split irregular shapes into sections and add the results together.
Ordering checks
The example uses 1.6 t/m3 density and 20 kg bags, giving 1.76 tonnes after allowance. Supplier bag weights, moisture, and delivery options can change the practical order.
- Compare small bags with bulk bags if the bag count becomes high.
- Check delivery access and where the aggregate can be dropped.
- Keep a small allowance for edging losses, settlement, and topping up.
20 m2 driveway gravel checks
| Input | Example value | Planning note |
|---|---|---|
| Area | 20 m2 | Finished surface area before depth is applied. |
| Depth | 5 cm | Changing depth changes volume directly. |
| Density | 1.6 t/m3 | Supplier figures should replace the default where available. |
| Order unit | 20 kg bags | 88 bags in this example after allowance. |
Example inputs used
- Length: 10
- Width: 2
- Depth: 5
- Aggregate density: 1.6
- Bag size: 20
These are starting values for this example. Measure or confirm your own figures, then open them in the gravel calculator.
Assumptions and limits
- Uses 10 x 2 m as a simple 20 m2 rectangle.
- Uses a typical decorative gravel density of 1.6 t/m3.
- Includes a 10% waste and settling allowance.
- Driveway construction may require separate sub-base material.
This is an estimate. Site conditions, compaction, and aggregate type can change the final quantity.