Garden & outdoor
How much gravel do you need for a garden path?
Cubic meters, tonnes and 25 kg bags of gravel for garden paths and driveways from area and depth.
Quick answer
Gravel is sold by the tonne but paths are measured in square meters — the missing variable is compacted depth. A 12 m² garden path at 5 cm with 10% allowance needs 12 × 0.05 × 1.1 = 0.66 m³. At bulk density 1.6 t/m³ that is roughly 1.06 tonnes — about 42 × 25 kg bags from the DIY yard, not "a couple of sacks".
Advanced settings
Volume to order
0.66 m³
- Weight (tonnes)
- 1.06 t
- 25 kg bags
- 43
Formula: m³ = area × depth × (1 + waste). Weight = m³ × density (t/m³). Lay geotextile under paths to stop mud mixing in; edge restraints keep gravel from spreading. Compact the sub-base before spreading.
How it works
Formula: m³ = area × depth × (1 + waste); tonnes = m³ × density. Foot traffic paths want 4–6 cm of pea gravel over compacted hardcore; car access needs 8–10 cm and a stronger sub-base. Lay geotextile before gravel so mud does not bubble up through the stone every winter.
The shape of the stone decides whether the path stays a path. Rounded pea gravel rolls under a foot and migrates steadily to the edges, so the middle goes thin within a season; angular crushed stone interlocks and stays where it is put — it is less pretty in the bag and far better underfoot. Whichever you choose, an edge restraint is not decoration: without a board, a kerb or a buried edging strip, every gravel surface spreads sideways until it is too thin to cover the sub-base, and topping it up each spring becomes an annual expense.
Frequently asked questions
How much gravel for a 20 m² path?+
At 5 cm depth + 10% waste: 20 × 0.05 × 1.1 = 1.1 m³. At 1.6 t/m³ → 1.76 tonnes (~70 bags of 25 kg). Depth drives the number more than area — 8 cm for light vehicle access pushes past 2.5 tonnes.
Do I need a sub-base under gravel?+
For foot paths: compacted hardcore or crushed stone 5–8 cm below the decorative gravel stops sinking. For driveways: proper road-base layers — this calculator sizes only the top gravel layer.
Pea gravel vs crushed stone?+
Pea gravel is comfortable to walk on and drains well — ideal for paths. Crushed stone with fines compacts harder — better for driveways and under patios. Densities differ slightly; adjust in advanced settings.
Why order 10% extra gravel?+
Compaction, uneven sub-base and spillage during spreading consume volume. Running short means a second delivery fee for one bag — the allowance is cheaper than a second trip.
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