Calculator 02 / Gravel & Aggregate
Gravel Calculator
Gravel is priced by weight but measured by volume, so the tonnage depends on the material's density as much as on the size of the hole. Estimate tons of gravel, crushed stone, sand, or topsoil for a driveway, base course, or fill area.
How this calculator works
Gravel and aggregate are sold by weight (tons), but you measure the job by volume. This tool converts your area and depth to cubic yards, then applies the material's density to get tons.
Worked example: a 20 × 12 ft driveway base
A 20 ft × 12 ft parking pad, 4 in of paver base at 105 lb/ft³, 10% waste:
- Area = 20 × 12 = 240 sq ft
- Depth = 4 ÷ 12 = 0.333 ft
- Volume = 240 × 0.333 = 80 cu ft
- Order volume = (80 × 1.10) ÷ 27 = 3.26 cubic yards
- Weight = 80 × 105 × 1.10 = 9,240 lb = 4.62 tons
- Weight without waste = 8,400 lb = 4.20 tons
Note that the yardage and the tonnage both carry the waste factor. They are two ways of describing the same order, and a supplier who quotes by the yard and one who quotes by the ton should be pricing the same pile.
What one cubic yard covers
A cubic yard is 27 cubic feet, so coverage is simply 324 divided by the depth in inches. This is the fastest sanity check on any quote — if the yardage does not roughly match your area at your depth, something is wrong.
| Depth | Area per cubic yard |
|---|---|
| 1" | 324 sq ft |
| 2" | 162 sq ft |
| 3" | 108 sq ft |
| 4" | 81 sq ft |
| 6" | 54 sq ft |
| 12" | 27 sq ft |
How deep to go
Depth is set by what the surface has to carry and by what is underneath it. The figures below are the minimum base thicknesses CMHA publishes for segmental pavers over well-drained soil, measured after compaction. CMHA says colder climates and continually wet or weak soils need thicker bases, but gives no single figure for them.
| Application | Minimum depth | Notes |
|---|---|---|
| Patio, walkway or sidewalk (pavers) | 4" | Compacted base over well-drained soil, plus about 1" of bedding sand, screeded loose |
| Residential driveway (pavers) | 6" | Compacted base over well-drained soil; CMHA calls for 4–6" lifts, thinner with a smaller plate compactor |
| Cold climate, wet or weak soil | Thicker | No single figure; ask a local contractor or an engineer. Geotextile is an option over clay or moist silty soil |
| Plain gravel driveway, garden path, French drain | No national standard | Follow your project specs or ask your supplier |
Which aggregate to ask for
Suppliers work in size numbers, not descriptions. Asking for "gravel" gets you whatever is nearest the loader. The distinction that matters most is whether the product contains fines: material with fines locks together and compacts, washed material stays loose and drains.
| Ask for | Size | Compacts? | Use |
|---|---|---|---|
| Crusher run / dense-graded base | Coarse stone down to fines | Yes | Base under pavers and driveways |
| #57 stone | 1" down to the #4 sieve (about 3/16") | No — open-graded | Drainage, such as around a perforated drain pipe |
| Pea gravel | Small and rounded; no standard size number | No — rounded pieces roll | Decorative surfacing, not a compacted base |
| Concrete sand (ASTM C33) | Sand | — | Paver bedding layer, about 1" thick |
| Stone dust / screenings | Fines | Unevenly | Not for paver bedding: CMHA says it often compacts unevenly and can block drainage in the bedding layer |
Density, and tons per cubic yard
The dropdown carries a density in pounds per cubic foot. Multiplied by 27 and divided by 2,000, that is the tons-per-yard figure a supplier will quote you. These are planning values, and real material varies with the rock, the gradation and how wet the pile is. Water has weight, so a rained-on pile weighs more than the same volume dry, and when you buy by the ton you pay for the water. Use your supplier's density for the exact product when they give one.
| Material | Density | Tons per cubic yard |
|---|---|---|
| Gravel / paver base | 105 lb/ft³ | 1.42 |
| Crushed stone | 100 lb/ft³ | 1.35 |
| Sand | 100 lb/ft³ | 1.35 |
| Decorative / river rock | 95 lb/ft³ | 1.28 |
| Topsoil | 76 lb/ft³ | 1.03 |
Where aggregate orders go wrong
- Compaction is not waste. Material with fines settles when it is compacted, so the loose depth you spread has to be greater than the finished depth. How much depends on the product, so ask your supplier and enter the loose depth. The waste factor covers spillage and over-dig, not compaction.
- Mixing up yards and tons. They are not interchangeable and the ratio changes with the material. Quote both to your supplier and let them reconcile.
- Using rounded stone as a base. Pea gravel and river rock are rounded and do not lock together the way crushed stone with fines does. For a base, ask for a dense-graded crushed product.
- Measuring the finished grade. Depth means excavated depth. If you measure down from where the surface will end up, you are a full course short.
- Ignoring delivery minimums. Many suppliers set a minimum load or charge extra for small deliveries. Ask before you order, and round up to what they will deliver, not to the estimate.
Gravel by the ton vs. the cubic yard
Not sure whether your supplier's tons and your cubic yards describe the same pile? Our guide to gravel by the ton vs. the cubic yard works through a 10 × 20 ft driveway, a 12 × 12 patio base and a walkway with this calculator, and lists the published minimum base depths.
Where these numbers come from
The size numbers on a quarry ticket come from a published gradation standard, not a local naming habit — which is why a #57 means the same thing in two different states.
- ASTM D448 — The standard classification of aggregate sizes, and the source of size numbers such as #57 stone.
- CMHA Tech Note PAV-TEC-002, Construction of Interlocking Concrete Pavements — Minimum compacted base thickness over well-drained soil for patios and walkways (4 in) and residential driveways (6 in), 1 in of bedding sand, why stone dust is not used for bedding, compaction lifts and when to use geotextile.
- NCDOT Table 1005-1, Coarse Aggregate Gradation — One state DOT's published gradation for the standard sizes, showing #57 stone running from 1 in down to the #4 sieve.
- National Stone, Sand & Gravel Association — Industry association for U.S. stone, sand and gravel producers.
- USGS construction sand and gravel statistics — Statistics on the U.S. and world supply of, and demand for, construction sand and gravel.
How deep should a gravel driveway base be?
For segmental pavers, the Concrete Masonry & Hardscapes Association (CMHA) gives minimum compacted base thicknesses over well-drained soil: 4 inches for patios and walkways and 6 inches for residential driveways, with thicker bases in colder climates and on continually wet or weak soils. There is no single national standard for a plain gravel driveway; follow your project specs or local practice.
Why does the same volume weigh differently depending on material?
Density varies by rock type, particle size, and moisture content. Always confirm density with your supplier's spec sheet for the exact product you're ordering.
Should I order by the ton or by the cubic yard?
Whichever your supplier quotes in — this calculator gives you both, and both include the waste factor, so they describe the same order. Yards are the safer unit to argue in, because a yard is a fixed volume while a ton of wet material occupies less space than a ton of dry. If a quote is priced by weight, ask what density they are assuming.
Does the waste factor cover compaction?
No. Waste covers spillage, over-dig and the material left in the truck. Compaction is separate: crusher run and other products with fines settle when they are compacted, so the loose depth has to be greater than the finished one. How much varies with the product and how it is compacted, so ask your supplier and enter the loose depth, rather than adding a guessed percentage to the waste factor.
Why is the order volume larger than the plain volume?
Because it includes your waste factor, matching the tonnage above it. The plain volume line is the raw geometry of the excavation. The order volume is what to actually buy. An earlier version of this calculator omitted the waste factor from the yardage while including it in the tonnage, so the two disagreed — that is fixed.
Can I save, share, or print a calculation?
Yes — use the Save, Copy link, and Print buttons under your results. Saved calculations can be grouped into a named project on the My Projects page for a combined job estimate with cost totals. Everything is stored only in your browser, never uploaded — see the Privacy Policy for details.
Estimates only. Suppliers may sell in fixed increments and set delivery minimums — confirm the exact yardage or tonnage and any minimums before ordering.