Gravel Driveway Calculator

How this calculator works

Gravel estimating is volume math with one twist that trips up almost everyone: the depth you want is compacted, but the material you order is loose. A 4-inch finished driveway takes more than 4 inches of delivered gravel, because rolling and traffic press the stone together by roughly 10–20%.

The calculator handles that in three steps:

compacted cu ft = area × (depth ÷ 12)
loose cu ft     = compacted × (1 + compaction %) × (1 + waste %)
tons            = loose cu ft × density (lb/cu ft) ÷ 2,000

Both volumes are shown in cubic feet and cubic yards (divide by 27), and the tonnage — which is how most quarries price and deliver — comes from an approximate loose density for the stone you pick: about 105 lb/cu ft for #57 crushed stone, 110 for crusher run, and 96 for pea gravel. Those are planning numbers, not lab values; your quarry can give you their exact conversion, which you can enter as a custom density in the advanced options.

Finally, the total tonnage is divided by your truck capacity to estimate how many deliveries you're looking at. If you enable the two-layer option, the base and top layers are calculated separately so you can order two different stones.

Worked example: a 50 × 10 ft driveway

Take a 50 × 10 ft driveway getting 4 inches of compacted #57 stone, with 15% compaction and 5% waste:

• Area: 50 × 10 = 500 sq ft.
• Compacted volume: 500 × (4 ÷ 12) = 166.7 cu ft = 6.17 cu yd in place.
• Loose volume to order: 166.7 × 1.15 × 1.05 = 201.3 cu ft = 7.45 cu yd.
• Weight: 201.3 × 105 ÷ 2,000 ≈ 10.6 tons — the calculator rounds the order up to 11 tons.
• Truckloads: at 15 tons per tandem load, that's one truckload.

Notice the gap between 6.17 compacted yards and 7.45 loose yards — about a yard and a quarter of material. Ordering the compacted number would leave the last 8–10 feet of this driveway bare.

How to measure a driveway for gravel

• Length: walk the centerline with a measuring wheel or long tape, from the road edge to the parking area. Include aprons and turnarounds by measuring them as separate rectangles and running the calculator once per section.
• Width:measure the surface you actually want covered. 10–12 ft is typical for a single car; add 2 ft if the drive curves so tires don't track off the edge.
• Depth for a refresh vs. new construction: topping up an existing drive usually takes 2–3 inches. A brand-new driveway over bare soil is a different project — plan on two layers totaling 6–8 inches (a large-stone base plus a smaller surface stone), which is what the two-layer option models.
• Slopes and soft spots:note any areas that pond water or rut. Those sections need extra base depth, better drainage, or geotextile fabric under the stone — extra material the calculator's waste percentage won't cover.

If cubic-yard math is new to you, the short guide Cubic Feet vs. Cubic Yards explains the conversions this calculator does behind the scenes.

Buying and ordering gravel

• Order by the ton when you can.Quarries weigh trucks, so tonnage is exact; "a yard" of gravel varies with moisture and how the loader heaps the bucket. This calculator shows both so you can compare quotes either way.
• Pick the right stone for each job. Crusher run (stone mixed with fines) locks together and makes the best base and surface for slopes. #57 stone drains beautifully but stays looser underfoot. Pea gravel migrates and ruts under car tires — keep it to paths and borders, not driveways.
• Ask about delivery minimums and spread. Many suppliers have a 3–5 ton minimum, and some drivers will tailgate-spread the load as they drive, saving you hours of raking. Both are worth a phone call before you order.
• Confirm truck access. A loaded tandem weighs over 25 tons — it can crack septic lids, sidewalks, and thin asphalt. Decide where the pile goes before the truck arrives.

Common estimating mistakes

• Ordering compacted volume instead of loose.This is the big one. The finished depth is measured after compaction; the truck delivers loose stone. Skipping the compaction factor shorts the order 10–20% — exactly the amount you'll be missing at the far end of the driveway.
• Using one ton-per-yard number for every stone. A loose yard of pea gravel (~1.3 tons) and a loose yard of crusher run (~1.5 tons) differ by hundreds of pounds. Match the density to the material, or get the conversion from your quarry.
• Dumping the full depth in one lift. Gravel compacts poorly beyond about 3 inches at a time. Spread and compact in 2–3 inch layers, wetting lightly between passes.
• Ignoring drainage rules. Many towns require a culvert where the drive meets the road, and grading that sheds water onto a neighbor can create a legal problem as well as a muddy one. Check before the stone arrives.
• Forgetting the crown. A good gravel drive is slightly higher in the middle (about 1/4 inch per foot of half-width) so water runs off. Flat-graded gravel ponds and potholes quickly.

Limitations

This tool models rectangular and circular areas with a uniform depth — measure winding driveways as a series of straight segments and add the results. Densities are approximate loose values that vary by quarry and moisture content, and the compaction factor is an estimate, not a soils-engineering number. It does not size culverts, design drainage, estimate geotextile fabric, or account for excavation and grading of the subgrade. For driveways on steep slopes or soft ground, a local contractor's advice is worth far more than a tighter material estimate.