Walk into any landscape yard and the first thing you will hear is not “what size bed?” - it is “which rock?” Pea gravel, crushed run, crusher run, river rock, 57 stone, 2B stone. They all look like a pile of gray rocks, but they behave completely differently once a car drives over them. Picking the wrong one is the most expensive mistake in this whole project, so start there before you measure a single foot.
Pick the stone before the depth
Pea gravel is the smooth, rounded, marble-sized stuff you see around patios. It drains well and looks clean, but the spheres roll - kick a shovel into it and the whole bed shifts. It belongs on footpaths, playground borders and between stepping stones, never on a driveway.
Crushed stone is mechanically broken rock with sharp, angular edges. When you tamp it, those edges interlock like jigsaw pieces and the layer actually hardens. This is the driveway and road base. Numbers like 57 stone or 2B stone just describe the screen size; for a residential driveway ask for crushed run or crusher run, which includes stone dust that fines the whole layer.
River rock is smooth and decorative, sold in sizes from 1 inch to fist-sized. It never compacts, it rolls under feet, and it works its way into lawn mowers over time. Use it in dry creek beds, around foundation plantings and as mulch substitute - not under tires.
The driveway thickness rule of thumb
A passenger-car driveway wants 4 inches of compacted crushed stone over a prepared sub-base. Walkways get by on 2 inches. Patios under furniture want 4 to 6 inches compacted in two separate lifts so the middle does not sink. French drains are a different geometry - 6 to 12 inches of clean angular rock around a perforated pipe, wrapped in filter fabric.
Because stone is sold by weight, the ton number matters more than the cubic yard number. Loose gravel lands around 1.4 to 1.7 tons per cubic yard depending on rock type and moisture. A tandem dump truck delivers 10 to 14 tons in one load; a half-ton pickup can carry about a ton without sagging the springs.
Worked example - a 20 by 40 ft driveway
Say you are resurfacing a suburban driveway that runs 20 ft wide and 40 ft long. At 4 inches deep, the volume comes to about 10 cubic yards before waste, which translates to roughly 15 tons of crushed run. Add 10 percent for the apron at the street and a few potholes you are filling, and you are ordering about 11 cubic yards or 16 tons. That is one and a half tandem loads - ask the yard whether splitting one truck is cheaper than two trips.
Bagged gravel is a trap for small jobs
At the hardware store you will see 0.5 cu ft bags of pea gravel on a wire rack. A 20 by 40 ft driveway would need hundreds of those bags at 10 times the price. Bags make sense for a 6 ft walkway or a small foundation planting. For anything bigger, call the quarry and price by the ton - delivery is often waived over a minimum load.
Layer it like the pros
The cheapest driveway is a properly layered one. Start with a compacted sub-base of 4 to 6 inches of larger quarry rock for structural strength, then the 4 inches of finished crushed run on top. Skip the structural layer and you will be filling ruts every spring. On a slope, stagger the lifts and roll each one before adding the next - a single 8-inch pour slumps downhill the first rain.
Gravel Calculator
Pick your stone, pace the driveway, and read out cubic yards and tons side by side - gravel is sold by the ton, so the weight number is the one your supplier quotes.
How to use
- Choose the stone first - pea gravel, crushed run or river rock each lock and drain differently
- Measure length and width in feet, or radius for circular beds
- Set depth - 4 inches compacted for a residential driveway, 2 inches for a footpath
- Add 10 percent waste for ragged edges and low spots
- Read the cubic yard and ton totals, then compare to the supplier's per-ton quote
Supported formats and limits
- Estimate only - coverage shifts with stone size, compaction and how well you tamp
- Weight assumed at 1.4 to 1.7 tons per cubic yard depending on the rock type
- Most suppliers sell by the ton, not by the bag - bagged gravel is for tiny patches only
- US units only - feet, inches, square feet and cubic yards
Examples
A 20 by 40 ft driveway at 4 inches deep comes to about 10 cubic yards before waste, roughly 15 tons, or about 16 cubic yards with 10 percent extra.Common errors
- Length and width must both be positive numbers
- Radius must be positive for circular areas
- Depth should fall between 1 and 12 inches - thinner layers wash out, deeper layers waste money
- Waste factor stays between 0 and 25 percent
Privacy and browser support
All measurements and calculations happen locally in your browser. Nothing leaves the device.
FAQ
How thick should a gravel driveway be?
Four inches of compacted crushed run is the residential standard for passenger cars. If you park an RV or truck, go to 5 or 6 inches and compact in two lifts. Two inches is plenty for a walkway where people never drive.
How many tons of gravel are in a cubic yard?
Roughly 1.4 to 1.7 tons per cubic yard. Crushed stone on the heavier end, pea gravel closer to 1.4. Because every landscape supplier quotes by the ton, the tool's ton output is the number you hand to the driver.
Pea gravel versus crushed stone - which is which?
Pea gravel is smooth, rounded and pretty, but it rolls underfoot and spreads under tires. Crushed stone is angular and locks together when tamped, which is why driveways wear crushed run. River rock looks decorative but never compacts - it belongs in dry stream beds, not under cars.
What stone goes in a French drain?
Clean 1.5 to 2 inch angular crushed stone, sometimes called drain rock. Never use rounded river rock in a drain - the smooth spheres leave channels that clog with silt, and pea gravel packs too tight. Line the trench with filter fabric first.
Do I buy gravel by the bag or by the ton?
Bagged gravel exists - usually 0.5 cu ft or 50 lb bags at the hardware store - but it is 5 to 10 times the per-ton price. Once your project tops a few hundred square feet, call a quarry and get a dump load.
Do I need landscape fabric under the gravel?
On a driveway over dirt, yes - fabric stops the stone from sinking into mud and cuts weeds. On a path over existing lawn, skips it unless the soil is soft. Never put fabric under a French drain trench itself; that belongs between soil and stone.
How long does a gravel driveway last?
Four or five years before ruts and potholes show up. A fresh 1 to 2 inch top-dress of crushed run each spring resets the surface cheaply. The base layer underneath can last decades if it was installed right.