ToolwickHow to Use This Gravel Driveway Calculator
Enter the length and width of your driveway, choose a unit for each, then enter the finished (compacted) depth of your base layer and pick the gravel type. If you plan a second layer of finer stone on top, enter its depth in the optional top-dressing box. Add a wastage percentage and, if you like, a price per ton, then press Calculate to get cubic yards, tons, truck loads and cost.
Why This Matters
Gravel is sold by weight but spread by volume, and that gap is where most ordering mistakes happen. Order too little and you pay a second delivery fee, often $75 to $200, plus a finished drive with a visible seam where two batches meet. Order too much and you are stuck with a pile of stone that costs money to haul away.
The numbers add up quickly. A modest 50 ft by 12 ft driveway at 4 inches deep needs about 11 tons of crushed stone once compaction is included. A 100 ft farm lane at the same width and depth needs about 22 tons. At a common $30 to $65 per ton, that is the difference between roughly $330 and $1,430 in material alone.
Depth drives cost more than anything else. Going from 3 to 6 inches doubles the stone you buy. Many contractors build a new drive as a base of larger crushed stone plus a thinner layer of finer stone on top, so this calculator handles both layers in one pass. Homeowners use it to budget, landscapers use it to bid, and anyone refreshing a worn drive can use it to see how little 1.5 to 2 inches of new stone really takes.
How It's Calculated
Everything is converted to feet first, then each layer is calculated separately and added together:
Order volume = Volume × (1 + Wastage %)
Tons = Order volume × Density (tons per yd³)
Total = Base layer + Top layer (if entered)
There are 27 cubic feet in a cubic yard, which is why the division by 27 appears. The wastage percentage covers stone that compacts when rolled, spreads past the edges or is lost in delivery. The density values (about 1.25 to 1.5 tons per cubic yard) are typical industry averages, not lab figures, and real loads vary with stone size and moisture.
To stay on the safe side, the calculator rounds the cubic yards, tons and cost up to the next hundredth rather than down, and it rounds truck loads up to a whole load at about 10 tons each. That load size is an assumption, so ask your supplier what their trucks actually carry. This is a material-quantity calculation, not a code formula, so there is no code edition to cite. Always follow local requirements for driveway aprons, drainage and materials.
Worked Example
Take the default values: a 50 ft by 12 ft driveway, a 4-inch layer of crushed stone (1.35 tons/yd³), 10% wastage and no top layer.
- Depth in feet: 4 in ÷ 12 = 0.3333 ft
- Volume: 50 × 12 × 0.3333 = 200 ft³
- Cubic yards: 200 ÷ 27 = 7.407 yd³
- Add 10% wastage: 7.407 × 1.10 = 8.148 yd³, shown as 8.15 yd³
- Tons: 8.148 × 1.35 = 11.00 tons, which is 2 truck loads at about 10 tons each
The calculator does not show a cost until you enter a price. If you type 45 in the price field, material cost is 11.00 × $45 = $495.00, and with a typical $75 to $200 delivery charge the total is about $570 to $695.
Now add a 2-inch top layer of the same stone: 50 × 12 × (2 ÷ 12) = 100 ft³, which is 3.704 yd³, or 4.08 yd³ with wastage and 5.50 tons. Together the two layers need 12.23 yd³ and 16.50 tons.
Tips & Common Mistakes
- Measure the real footprint. Include turnarounds, parking pads and the flared entrance. A 5 ft error on a 50 ft drive is a 10% error, about a ton of stone.
- Enter compacted depth, not loose depth. Freshly dumped stone is thicker than the finished surface. The wastage field exists to cover that difference.
- Use 15% to 20% wastage over soft or uneven ground. Stone sinks into soft subgrade, so a thin 10% allowance is a minimum for a well-prepared base.
- Don't enter two layers as one depth. If the layers use different stone, use the top-layer fields so each gets its own density.
- Ask for the supplier's tons-per-yard figure. The numbers here are averages, and an order of 20 or more tons can be off by a ton or two if the real density differs.
- Check delivery minimums and truck access. Many yards set a minimum order, and a loaded dump truck needs clear overhead and firm ground.
Frequently Asked Questions
How deep should a gravel driveway be?
A common rule of thumb for a new residential driveway is about 4 to 6 inches of compacted stone in total, often a 4-inch base of larger crushed stone plus 2 inches of finer stone on top. Topping up an existing drive usually needs only 1.5 to 2 inches. Heavy vehicles, soft soil or poor drainage call for more, and local rules may set their own requirements.
How many tons of gravel are in a cubic yard?
Most gravel weighs about 1.25 to 1.5 tons per cubic yard. Crushed stone averages roughly 1.35, pea gravel about 1.4 and limestone about 1.5. Moisture and stone size change the figure, so confirm it with your supplier.
How much gravel do I need for a 100 ft driveway?
At 12 ft wide and 4 inches deep, a 100 ft driveway is 400 ft³, or 14.81 yd³. With 10% wastage that becomes 16.30 yd³, which is about 22 tons of crushed stone. Change the length and depth in the calculator to see your own numbers.
How much does a gravel driveway cost?
Material often runs $30 to $65 per ton depending on the stone and your region. Delivery typically adds $75 to $200, and hired spreading and compaction can add several hundred dollars more. Enter your local price per ton to get a figure for your own job.
Does this calculator include compaction and spillage?
Yes. The wastage percentage, 10% by default, is added on top of the raw volume for compaction, uneven spreading and delivery loss. Raise it to 15% or 20% for soft ground, slopes or rough sites.
Can I use it for a gravel path or parking pad?
Yes. The math is length × width × depth for any rectangular area, so it works for paths, parking pads, patios and drainage beds. For a shape that is not rectangular, split it into rectangles and add the results.