Example 1
- 10 × 3 × 0.1 m
- 1600 kg/m³
- +5% waste
3.15 m³ · 5.04 t
100 mm layer + 5% waste - a typical garden path.
Gravel requirement calculator
Type length, width, thickness, and density. The calculator computes V, adds waste, and mass. A 10×3×0.1 m strip at 1600 kg/m³ and 5% is 3.15 m³ and 5.04 t.
Results are indicative. Loose and compacted gravel differ in density; suppliers may sell by the tonne or bulk bag. Also see concrete volume and sand.
Results
Length, Width, Depth / thickness and Waste (%). The result shows up here.
How results are calculated
Gravel requirement counts m³, tons, bulk bags, and small bags. V = length times width times thickness times (1 plus waste). Mass = V times density in kg/m³. Bulk bags are ceil(V divided by bag volume). Small bags are ceil(mass divided by bag size).
A 10 by 3 m drive 10 cm thick at 1600 kg/m³ and 5% is 3.15 m³ and 5.04 t. An 8 by 4 m base 15 cm at 10% is 5.28 m³ and 8.45 t. A 5 by 2 m path 8 cm at 1500 kg/m³ and 5% is 0.84 m³ and 1.26 t. Sand on 6 by 4 m and 5 cm is 1.26 m³ next door.
Type length, width, and depth in the header unit. Ten centimeters is 0.1. Waste, preset, custom density, bulk bag, small bag, and price are optional. Density stays in kg/m³ even with US labels, the usual bulk delivery unit.
Sand and topsoil share this layout. Concrete 2.1 m³ from a 5×4×0.1 m slab lives on concrete volume, a different material. A 10 by 3 m plan is 30 m² on floor area.
Loose and compacted gravel differ in density. 5.04 t at 1600 kg/m³ is an estimate, not the weight after a roller. Bags and bulk bags round up. Typing 10 as thickness instead of 0.1 orders a hundred times too much.
Type 10, 3, and 0.1, set 1600 and 5%, click Calculate, and match 3.15 m³ and 5.04 t. Then 8, 4, and 0.15 at 10%: 5.28 m³ and 8.45 t.
How to use this calculator
- Type length, width, and thickness in the header unit. A 10 cm layer is 0.1, not 10.
- Set waste, usually 5-10%, and density, for example 1600 kg/m³ from a preset.
- Optionally enter bulk-bag volume and bag size if that is how you buy.
- Click Calculate. 10×3×0.1 m, 1600 kg/m³, and 5% give 3.15 m³ and 5.04 t.
- Sand and concrete sit next door. This calculator stays bulk gravel.
V and t on gravel
10×3×0.1 m at 1600 kg/m³ and 5% is 3.15 m³ and 5.04 t. A 5×2×0.08 m path is 0.84 m³ and 1.26 t.
- m³
- Volume after waste. 3.15 from the 10×3×0.1 strip. 0.84 from the path. A 0.5 m³ bulk bag is 7 pieces.
- t
- Mass. 5.04 t from 3.15 m³ × 1600 kg/m³. Bags from that tonne go through ceil.
Practical tips
- Path: often about 50-100 mm of gravel over geotextile and a compacted base.
- Driveway: typically thicker (about 100-150 mm) plus a proper sub-base for vehicles.
- Buying: compare price per m³, per tonne and per bulk bag - density changes the maths.
Usage examples
Example 2
- 8 × 4 × 0.15 m
- 1600 kg/m³
- +10% waste
5.28 m³ · 8.45 t
Thicker layer and more waste for vehicle traffic.
Example 3
- 5 × 2 × 0.08 m
- 1500 kg/m³
- +5% waste
0.84 m³ · 1.26 t
Fine gravel with 25 kg bags - handy for a small job.
Example 4
- 12 × 3.5 × 0.12 m
- 1600 kg/m³
- +8% waste
5.44 m³ · 8.71 t
How much gravel for a 12×3.5 m driveway 12 cm thick? 5.44 m³, 8.71 t.
Example 5
- 6 × 4 × 0.10 m
- 1600 kg/m³
- +5% waste
2.52 m³ · 4.03 t
How much gravel under a 6×4 m patio at 10 cm? 2.52 m³, 4.03 t.
Example 6
- 20 × 0.8 × 0.08 m
- 1500 kg/m³
- +10% waste
1.41 m³ · 2.11 t
How much gravel for a 20 m garden path 80 cm wide? 1.41 m³, 2.11 t.
Example 7
- 8 × 5 × 0.15 m
- 1800 kg/m³
- +10% waste
6.60 m³ · 11.88 t
How much compacted gravel for an 8×5 m parking pad 15 cm thick? 6.60 m³, 11.88 t.
Example 8
- 25 × 0.4 × 0.40 m
- 1600 kg/m³
- +5% waste
4.20 m³ · 6.72 t
How much gravel for a 25 m French drain 40×40 cm? 4.20 m³, 6.72 t.
Related calculators
Frequently asked questions
How much gravel for 10×3×0.1 m at 1600 kg/m³ and 5%?
3.15 m³ and 5.04 t. 10×3×0.1 = 3, times 1.05, times 1600 kg/m³.
How much at 8×4×0.15 m, 1600 kg/m³, and 10%?
5.28 m³ and 8.45 t. A thicker base, a higher waste. Same V formula.
How much at 5×2×0.08 m, 1500 kg/m³, and 5%?
0.84 m³ and 1.26 t. A path, a lighter density. Product 5×2×0.08 = 0.8, then waste.
How do I type a 10 cm thickness?
As 0.1 m. Typing 10 would be ten meters of stone, a hundred times too much for a path.
What waste should I add for gravel?
Usually 5-10% for compaction and edges. 5% on 3 m³ is 0.15 m³.
Is a 0.5 m³ bulk bag 7 pieces at 3.15 m³?
Ceil(3.15 / 0.5) = 7. Small bags from tons are separate from bulk bags.
How much sand for 6×4×0.05 m?
1.26 m³ and 2.02 t on the sand page. The same V formula, a different thickness.
How much concrete for a 5×4×0.1 m slab?
2.1 m³ at 5% on the concrete calculator. Gravel under the slab you count here.
Is 5.04 t the weight after compaction?
It is V times the density you typed. Loose and compacted gravel differ; pick the preset.
Do bags round up?
Yes. Mass divided by bag size goes through ceil. A fraction of a bag is bought as a full bag.
Knowledge sources
Volume and waste come from the sizes you type. Below are volume and NIST SI units.
Page updated in 2026.