Gravel Calculator

How much gravel do I need?

The amount of gravel depends on three things: the area you're covering, the depth you need, and the type of gravel. Different projects need different depths — a driveway needs at least 4 inches to handle vehicle weight, while a decorative garden bed only needs 2 to 3 inches.

Recommended depths by project

Driveways need a minimum of 4 inches of compacted gravel; 6 inches is better for heavier vehicles or soft ground. Garden paths and walkways work well at 2 to 3 inches. Decorative beds around plants and borders need 2 inches. French drains and drainage channels typically require 6 to 12 inches of clean gravel.

Cubic yards vs. tons vs. bags

Suppliers in the US sell bulk gravel either by the cubic yard (volume) or by the ton (weight). Always ask your supplier which unit they use before ordering. Small quantities are also available in 50 lb bags at home improvement stores — practical for projects under 1 cubic yard, but significantly more expensive per unit than bulk delivery. In the UK, bulk gravel is typically sold by the tonne (metric ton), with bag sizes of 25 kg being standard.

Why gravel compacts

Fresh gravel contains air gaps between the stones. Once spread and exposed to foot traffic, vehicle weight, or rain, those gaps compress — reducing the actual depth by 15% to 30% depending on gravel type. This calculator already accounts for that compaction, so the quantities shown are ready to order without adding an extra buffer.

Choosing the right gravel type

Crushed stone and crushed gravel are angular and lock together well, making them the standard choice for driveways and high-traffic areas. Pea gravel is smooth and round — comfortable underfoot on paths but not suitable for driveways because it shifts. River rock is decorative and works well in beds and borders. Lava rock is very lightweight and good for low-maintenance decorative areas. Limestone and caliche are common base materials for drainage systems and subbase layers.