Gravel Calculator
| Project | Volume | Weight |
|---|---|---|
| Two-car driveway 20 x 40, 4 in | 9.9 yd³ | 13.8 t |
| Garden path 3 x 40, 3 in | 1.1 yd³ | 1.6 t |
| Patio base 12 x 14, 4 in | 2.1 yd³ | 2.9 t |
| Play area 15 x 15, 6 in | 4.2 yd³ | 6.0 t |
| French drain 50 x 1.5, 12 in | 2.8 yd³ | 4.3 t |
Gravel is sold two ways at once - by the cubic yard to landscapers and by the ton at the quarry gate - and the two answers are not the same number, which is why every gravel order starts with this conversion: area times depth gives volume, then the stone's bulk density turns yards into tons. One cubic yard of crushed stone runs about 1.4 tons; river rock is denser and rounder at roughly 1.55. Get the unit wrong and you either pay for a second delivery or shovel the surplus all summer.
Depth is the specification that decides everything. A driveway needs about four inches of compacted stone over a base so the surface does not pump or rut; a decorative border or garden path sits at two to three inches; a play area with rounded pea stone goes six inches for cushion. Doubling the depth doubles the tonnage - the calculator shows the ton and yard figures for any depth so the delivery quote can be checked line by line.
The national price context comes from the USGS Mineral Commodity Summaries, which tracks crushed stone as the country's leading nonfuel mineral commodity: about 1.5 billion tons a year, at an average unit value of $18.50 per metric ton in the 2025 estimate - roughly $16.80 per short ton. Quarries price above that mine-gate average once delivery is loaded in, so treat the national number as the floor the local quote competes against, not the quote itself.
How to use
- Measure the length and width of the area in feet and pick the depth in inches - four for a driveway, two to three for decoration, six for play areas.
- Pick the stone type: crushed stone interlocks for driveways, pea gravel drains and stays friendly underfoot, river rock is the heaviest and the most decorative.
- Order in the unit your supplier sells: the tons figure for quarry deliveries, the cubic yards figure for bagged or landscaper-sized loads - and add ten percent for compaction on anything that will be driven on.
Frequently asked questions
How many tons of gravel are in a cubic yard?
About 1.4 tons for crushed stone, roughly 1.45 for pea gravel and up to 1.55 for dense river rock - one cubic yard is 27 cubic feet, and the stone's bulk density does the conversion. Wet gravel runs heavier still: rain-soaked deliveries can add ten percent to the scale, which is one more reason the ten-percent ordering cushion earns its keep.
How deep should a gravel driveway be?
Four inches of compacted surface stone over a prepared base is the working standard - two inches packs down to almost nothing under a tire. Soft clay soils want a base course of larger stone underneath, which is a separate layer with its own tonnage. For a 20-by-40-foot two-car driveway at four inches, expect about 9.9 cubic yards - roughly 13.8 tons of crushed stone delivered.
How much area does a ton of gravel cover?
At the common 1.4 tons per yard, one ton is about 0.71 cubic yards, which covers roughly 80 square feet at three inches deep or 120 square feet at two inches. Working the other direction: a 100-foot garden path three feet wide at three inches takes about 1.4 tons - one quarry scoop, usually sold as a half-ton minimum for small loads.
Why does the calculator show both yards and tons?
Because the industry splits at the sale: landscape suppliers talk yards, quarries and trucking companies weigh tons at the scale house. Gravel is the rare material where both units are standard, and the density bridge between them (tons per cubic yard) is where most online calculators quietly pick a single stone type and hope. A yard of river rock and a yard of crushed stone are different weights, so both numbers are shown and the stone type does the converting.
Do I need to compact gravel, and how much extra should I order?
Driven surfaces compact - loose stone settles 10 to 15 percent once it has been rolled and rained on, so order about ten percent extra beyond the nominal volume. Decorative ground cover that never gets traffic does not compact meaningfully and can be ordered at the calculated figure. Compaction is also why depth is specified after tamping for driveways: four inches compacted means four inches once settled, not four inches of loose dump.
What is the price per ton of gravel?
The USGS national average unit value for crushed stone was $18.50 per metric ton in the 2025 estimate - about $16.80 per short ton at the mine gate. Delivered prices stack loading and trucking on top, and small residential loads carry a delivery minimum that dominates the bill; the honest move is to price the tonnage here, then compare two local quotes against that floor.