Over-excavation, spillage and uneven subgrade. 5-10% for formed work, 10-15% on rough ground.
Loose aggregate loses volume when it is rolled. Order the loose volume, not the finished volume.
Optional. Leave at zero to skip the cost estimate.
Material quantity estimate for planning and purchasing. Not structural engineering advice, not a bid, and not a code determination.
Gravel is sold by weight, so density matters
Bulk aggregate is priced and delivered by the ton, but you measure your project in volume. Getting between the two needs a density, and a lot of calculators skip the step and just relabel cubic yards as tons — which understates a gravel order by about 35%.
This page uses 2,700 lb per cubic yard (1.35 tons) for #57 crushed stone, which is the standard planning figure. Your quarry will have the real number for their material and it is worth asking, because the spread between pea gravel and dense-graded base is meaningful on a large order.
| Material | Tons per yd³ | Typical use |
|---|---|---|
| Pea gravel, 3/8 in | 1.30 | Paths, play areas, pipe bedding |
| #57 crushed stone, 3/4 in | 1.35 | Drainage, slab base, French drains |
| #411 / CA6 dense-graded base | 1.45 | Driveway base, compacts hard |
| Crushed concrete | 1.35 | Budget base course |
| River rock, 1-3 in | 1.30 | Decorative, does not compact |
The compaction allowance
This is the field most calculators do not have, and it is the one that stops you ordering 20% short.
Loose aggregate loses volume when it is rolled or plate-compacted — dense-graded base drops about 20-25%, clean drainage stone closer to 10-15%, and decorative river rock essentially none because it does not interlock. If you need a finished compacted depth of 4 inches, you have to order more than 4 inches of loose material.
The default here is 20%, which suits a compacted base course. Drop it to 0 for decorative stone you are not compacting.
How much fits on a truck
Delivery comes in fixed sizes, so it is worth knowing where the steps are: a standard tandem dump carries about 12-15 tons, a tri-axle 18-22 tons, and a small landscape truck 5-6 tons. Below about 3 tons most yards charge a flat delivery fee that dwarfs the material cost, and it is usually cheaper to collect a pickup load — though note a half-ton pickup is legally and structurally done at about 1 cubic yard of wet gravel, which is a ton and a half.
Common questions
How many tons of gravel in a cubic yard?
About 1.35 tons for #57 crushed stone, 1.30 for pea gravel, and 1.45 for dense-graded base. A cubic yard of gravel weighs roughly 2,700 lb, so the two numbers are not interchangeable.
How much gravel do I need for a 40x12 area?
At 4 inches deep, 40 x 12 ft is 160 cubic feet or 5.93 cubic yards loose. Add a 20% compaction allowance and you need 7.1 cubic yards, which is about 9.6 tons of #57 stone.
How deep should gravel be?
Two inches for a decorative bed, 3-4 inches for a garden path, 4 inches minimum under a slab, and 8-12 inches in layers for a driveway carrying vehicles.
Should I order by the ton or by the yard?
Take whichever your supplier quotes and convert with their density. Tons are more common for bulk and are what the truck scale measures. Just make sure you and they mean the same thing — ordering "six yards" and being billed for eight tons is a common and expensive misunderstanding.