A standard 2-car driveway of 24 × 24 ft is 576 sq ft. Paved in asphalt 3 in thick over 6 in of crushed stone it takes 10.44 tons of hot mix and 19.73 tons of base stone (11.48 and 21.71 tons with 10% extra), and costs about $5,800 installed at the US average. The same pad in concrete 4 in thick is 7.11 cubic yards; in gravel, three 4 in layers come to about 33 tons of stone.
How the driveway calculator works
Every surface starts from the same plan area, then turns it into what the supplier sells:
asphalt tons = area × thickness × 145 lb/ft³ ÷ 2,000 · concrete cu yd = area × thickness ÷ 27 · stone tons = area × depth ÷ 27 × tons per cu yd
The area depends on the shape you pick:
- Straight: length × width.
- Flared apron: the drive widens at the street so cars can swing in without cutting the corner. The calculator adds two triangles: extra width on each side × apron length. A 40 × 12 ft drive with 3 ft of flare each side over a 6 ft apron gains 3 × 6 = 18 sq ft, for 498 sq ft.
- Turnaround: a round pad at the house end, π × diameter² ÷ 4. A 36 ft circle adds 1,018 sq ft, more than the whole 2-car pad, which is why turnarounds are the first thing to cut from a tight budget.
The base under asphalt or concrete is priced as dense-graded crushed stone at 1.85 tons per compacted cubic yard, the unit weight WSDOT's design manual gives for crushed surfacing base course.
Worked example: 2-car driveway, 24 × 24 ft
| Surface | Material (net) | With 10% extra | Installed, US average |
|---|---|---|---|
| Asphalt, 3 in on 6 in base | 10.44 tons hot mix, 19.73 tons base | 11.48 and 21.71 tons | $5,800 ($4,050 to $8,600) |
| Concrete, 4 in | 7.11 cu yd | 7.82, order 8 cu yd | $5,200 ($4,600 to $6,900) |
| Gravel, 3 layers of 4 in | 33.1 tons of stone | 36.4 tons | $1,750 ($1,000 to $3,000) |
The asphalt line checks out by hand: 576 sq ft × 0.25 ft = 144 cu ft, × 145 lb = 20,880 lb, ÷ 2,000 = 10.44 tons. The installed prices are Fixr's national figures per square foot for each surface ($7 to $15, most around $10, for asphalt; $8 to $12 for broom-finished concrete, $9 typical; about $3 for gravel) times your area, scaled to your state and rounded.
1-car and 2-car driveway sizes
Fixr's cost guides use 10 × 20 ft for a single stall, 12 × 24 ft for a single, 20 × 20 ft for a double stall and 24 × 24 ft for a double. The presets fill the length and width with the 12 × 24 and 24 × 24 ft sizes; change either field and the plan redraws. A 12 × 24 ft single in 3 in asphalt is 288 sq ft and 5.22 tons of hot mix.
Asphalt, concrete or gravel: the thickness behind the defaults
- Asphalt: 3 in in two 1 ½ in lifts over 6 to 8 in of compacted stone, or 4 to 6 in full depth for a stronger drive (Illinois Asphalt Pavement Association). The association rates 1 in of asphalt as equal to 3 in of stone base, so thin asphalt needs a thick base.
- Concrete: at least 4 in, 5 in where a heavy truck parks, 3,000 to 4,000 psi, on a sub-base of a few inches to a foot depending on the soil (Fixr).
- Gravel: a #3 base, a #57 middle layer and a crusher run top, ideally 4 in each for 12 in (Fixr). The gravel driveway calculator lets you change each layer, add geotextile fabric and edging, and prices the stone by the ton.
What the base course does
The base carries the load and drains water away from under the surface. On soft clay or wet ground, thicken it or add fabric rather than paving thicker. The drawing under the result shows the layers to scale with your numbers, so you can see how much of the driveway is stone you will never look at.
Next questions
- Hot mix by lifts and truckloads: the asphalt calculator.
- Pouring concrete: bags, trucks and thickened edges are in the concrete slab calculator, and the concrete cost calculator prices the pour.
- Building on a hill: check grades and grade changes with the driveway slope calculator.
- Keeping asphalt black: the driveway sealer calculator.
All paving tools are on the driveways and paving hub.