Gravel Calculator
Estimate how much gravel you need for a driveway, path or base — in cubic yards and tons — using your area, depth and the material's bulk density.
Result
| Volume | |
| Weight |
Units & conversions used
Imperial inputs are square feet (area) and inches (depth); results are shown in cubic yards (1 yd³ = 27 ft³), US tons, cubic meters and metric tonnes. Metric inputs are converted first: 1 m² = 10.7639 ft², 1 cm = 0.3937 in; 1 US ton = 0.9072 tonnes.
Formula & source
tons = V(yd³) × density(tons/yd³)
Source: basic geometry for the volume step; the weight step is volume × bulk density. The default density of 1.5 tons/yd³ is a stated assumption, not a measured value for your material: typical crushed stone runs about 1.35–1.7 tons/yd³ depending on rock type, size and compaction, and your supplier's figure is the one that counts — enter it in the density field above.
Worked example (you can verify by hand)
Input: 100 ft² area × 3 in deep, density 1.5 tons/yd³.
- Volume: 100 × 3 ÷ 12 = 25 ft³
- Cubic yards: 25 ÷ 27 = 0.9259 yd³
- Weight: 0.9259 × 1.5 = 1.3889 tons
Expected output: 0.93 yd³ (0.71 m³) = 1.39 tons (1.26 tonnes).
Limitations — what this cannot do
- Weight is an estimate: bulk density varies with rock type (limestone, granite, river rock), aggregate size and how compacted it is. If the supplier quotes weight per yard, use their number.
- Assumes a level area of uniform depth. Sloped ground and soft subgrade that settles will need extra material.
- Does not account for compaction: loose depth shrinks roughly 20–30% when compacted, so compacted depth may need a thicker loose layer.
FAQ
How many tons of gravel do I need for a 100 sq ft area at 3 inches deep?
100 × (3 ÷ 12) ÷ 27 = 0.93 yd³, and at the default 1.5 tons/yd³ that is 1.39 tons (1.26 tonnes). Confirm the density with your supplier before ordering.
What density should I use for crushed stone?
Typical crushed stone is about 1.35–1.7 tons per cubic yard; 1.5 is a common middle value used here as the default. River rock and pea gravel differ, so adjust the field if you know your material's density.
How many cubic yards are in a ton of gravel?
It depends on density: tons ÷ density = yards. At 1.5 tons/yd³, one ton is about 0.67 yd³. Denser stone gives fewer yards per ton.
Does compaction change how much gravel I need?
Yes. Gravel compacts roughly 20–30% under rolling, so a 4-inch compacted driveway layer needs about 5–5.5 inches of loose material. This calculator works in loose depth; add extra if you need a finished compacted depth.
Is this calculator for crushed stone, pea gravel, or river rock?
Any of them — the volume math is the same for all. Only the density differs, which is why the density field is adjustable. Enter your supplier's tons-per-yard figure for the exact product you are buying.
How much does a gravel driveway cost?
Published cost guides (e.g., Angi) commonly cite $1.25–$2.00 per square foot installed for a basic gravel driveway — so a 12×50 ft driveway (600 ft²) typically runs about $750–$1,200. That range assumes a standard 4–6 inch depth with basic grading. Costs rise with:
- Site prep — excavation, grading, and landscape fabric or geotextile.
- Depth and layers — a proper driveway often has a compacted base layer plus a top layer.
- Edging and drainage — borders to hold gravel in, and any culvert or grading work.
- Delivery distance — haul charges from the quarry add up fast.
Use the calculator above to get your cubic yards and tons first, then ask local suppliers for per-ton delivered pricing — material is often only half the total.