Gravel calculator
Compute gravel volume in cubic feet and yards, then tons by material type, for driveways, pad work and fence post bases.
Gravel needed
Enter your measurements and the result updates as you type.
Overview
Gravel is sold two ways, by the cubic yard and by the ton, and the two disagree unless you know the material. This calculator multiplies length times width times depth for the volume, then converts to tons using the loose bulk density of the gravel, crushed stone, pea gravel or sand you pick.
Ordering moves by weight when you have a volume: 1.4 tons per loose cubic yard of gravel is the common conversion, with crushed stone a bit heavier and sand lighter again.
Common mistakes
- Ordering a tonnage number that came from a different material's density and is off by 20 percent or more.
- Forgetting that the depth input in inches drives the volume, so a 4 inch pad and a 4 foot pad are 12 times apart, not equal.
- Buying by eyepatch instead of volume, then having a half-delivered pad at the end of the project.
Related calculators
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- Fence post calculator Calculate line posts, corner posts and end posts from run length and spacing, with concrete for each post included in the take-off.
- Retaining wall calculator Work out blocks per course, courses and total blocks for a retaining wall from wall dimensions and block size, including the buried base course.
Related reading
In-depth guides
Frequently asked questions
How many tons of gravel do I need for a 40 by 4 foot pad at 4 inches?
The volume is 40 by 4 by 0.333 feet, or 53.3 cubic feet, which is 1.98 cubic yards. At the 1.4 tons per cubic yard figure for gravel that is about 2.77 tons, so order roughly 2.8 tons to be safe.
What is the gravel formula?
Multiply length by width by depth (depth in feet equals inches divided by 12) to get cubic feet, divide by 27 for cubic yards, then multiply by the material density in tons per cubic yard for the weight.
Why do crushed stone and pea gravel give different tonnage?
Because their loose bulk densities differ: crushed stone stacks heavier at about 1.6 tons per cubic yard, pea gravel closer to 1.5, plain gravel 1.4, and sand only 1.35. Same volume, different weight, which is why a single "tons per yard" number does not exist.
Should I order gravel by the yard or by the ton?
Suppliers quote either unit depending on the product and region, so to compare quotes you need both: the volume for the pad and the weight the density predicts, which is exactly what this calculator returns side by side.
How thick should a gravel base be under a fence?
A base of 3 to 4 inches is the common depth for a fence line or post base before concrete or for gravel-set posts, and this calculator accepts that depth directly in inches.
Can I set fence posts in gravel instead of concrete?
Yes, in free-draining sandy or rocky ground gravel backfill works and drains, which some builders prefer for economy and drainage. It holds less rigidly than concrete, so choose it where drainage matters more than rigidity.
How much gravel does a 10 by 10 shed pad need at 4 inches?
100 square feet at 0.333 feet is 33.3 cubic feet, or 1.23 cubic yards, which is about 1.73 tons of standard gravel. That is the short answer this calculator reproduces for any pad size.
Does gravel need a compacted depth or a delivered depth?
Delivered depth settles under compaction, sometimes by a quarter or more, so plan the pad with a bit of extra depth and compact in lifts. Treat the calculator's volume as the pre-compaction order for clean topsoil work.