Gravel Calculator

Calculate Gravel

m
m
cm

Volume

0.75 m³

Cubic Yards

0.98

Weight

1.13 tonnes

Avg density ~1.5 t/m³

How This Calculation Works

The gravel calculator computes the volume of material needed by multiplying area (length × width) by depth. It converts the depth from centimetres or inches into metres or feet before multiplying, then displays the result in cubic metres, cubic feet, and cubic yards.

Because gravel is sold by weight, the calculator also estimates tonnage. It uses an average bulk density of 1.5 tonnes per cubic metre (or 1.35 US tons per cubic yard), which is typical for common crushed stone and pea gravel. Actual density varies: river rock and dense granite may be heavier, while lightweight pumice or lava rock will be lighter.

Always confirm density with your supplier when ordering by weight.

Common Mistakes to Avoid

  • Too-thin gravel layer. A driveway needs at least 10–15 cm (4–6 in) of compacted gravel. Pathways can be thinner (5–7.5 cm), but less than that and the base soil shows through quickly.
  • Ignoring compaction. Loose gravel compacts by about 20–30% when driven over or tamped. Order extra to account for settling.
  • Wrong gravel type. Decorative pea gravel shifts underfoot and isn't suitable for driveways. Use angular crushed stone (e.g., ¾-inch minus) that locks together when compacted.
  • Skipping landscape fabric. Without a weed barrier underneath, weeds will grow through gravel within a season. Install landscape fabric before spreading gravel.

Worked Example

Scenario: A garden path 5 m long × 1.5 m wide, 5 cm deep with pea gravel.

Step 1 — Area: 5 × 1.5 = 7.5 m².

Step 2 — Volume: 7.5 × 0.05 = 0.375 m³.

Step 3 — Cubic yards: 0.375 ÷ 0.7646 ≈ 0.49 yd³.

Step 4 — Weight: 0.375 × 1.5 = 0.56 tonnes. Order about 0.6 tonnes (a little extra for compaction).

Frequently Asked Questions

How deep should gravel be for a driveway?
A gravel driveway typically needs 10–15 cm (4–6 in) of compacted material. This is usually applied in two layers: a 10 cm base of larger crushed stone topped with 5 cm of finer gravel. For heavy traffic, go deeper.
How much does a cubic metre of gravel weigh?
On average, 1 cubic metre of dry gravel weighs about 1.5 tonnes (1,500 kg). This varies by stone type — denser materials like granite can reach 1.7 t/m³, while lighter materials may be 1.3 t/m³.
Should I compact the gravel?
Yes, for driveways, patios, and paths. Use a plate compactor or hand tamper in layers of 5–7.5 cm. Compacted gravel creates a stable surface that resists shifting and rutting.
How much extra should I order?
Order 10–15% more than calculated to account for uneven ground, compaction, and minor spreading losses. It is far easier to order slightly too much than to run short and pay for a second delivery.