Concrete Driveway Estimator
Enter the main driveway rectangle. Edges, apron, base, steel and prices are below the results.
Driveways & Paving
Concrete Driveway Calculator
Quick answer: driveway concrete (yd³) = length × width × thickness in feet ÷ 27, plus about 10% waste. A 50 ft × 12 ft driveway poured 4 in thick is 200 ft³ = 7.41 yd³ — order about 8.2 yd³ — over roughly 12.4 tons of 4 in gravel base.
Plan a poured concrete driveway in one pass: ready-mix yards and trucks (including thickened edges and a street apron), compacted gravel base, rebar or wire mesh, control-joint footage, and a material and installed cost range.
Driveway cross-section
How to calculate concrete for a driveway
A driveway is a long, thin slab, so most of the concrete is plain length × width × thickness. The pieces people forget are the thickened edges along the sides, the flared apron where the drive meets the street, and the waste that comes from an uneven subgrade. Those three items routinely add 10–20% to a quick rectangle estimate.
[(L × W + Apron) × T + Edge run × Edge W × Extra D] ÷ 27
all dimensions in feet · result in cubic yards before waste
- Measure the main rectangle. Length from the garage slab to the property line or apron, and the finished width (10–12 ft for one car, 18–24 ft for two).
- Pick a thickness. Convert inches to feet (4 in = 0.333 ft) and multiply by the area for cubic feet.
- Add the apron or flares. Measure the flared area in square feet and multiply by the same thickness, unless the city detail calls for a thicker apron.
- Add thickened edges. Edge run × edge width × extra depth. Only the concrete below the normal slab bottom is extra.
- Divide by 27 and add waste. 5–10% for a well-graded base, more if the subgrade is rough.
- Size the base and steel. Base area × depth plus a compaction allowance, converted to tons; rebar grid lines or mesh sheets for the same footprint.
Worked example
A single-car driveway is 50 ft long and 12 ft wide, poured 4 in thick. Both long sides are thickened 2 in over a 12 in width, and the street flare adds 40 ft². It sits on a 4 in crushed-stone base with #3 rebar at 18 in on center and control joints every 10 ft.
- Slab: 50 × 12 × 0.333 = 200.0 ft³; apron: 40 × 0.333 = 13.3 ft³
- Edges: 2 sides × 50 ft × 1 ft × 0.167 ft = 16.7 ft³
- Net 230.0 ft³ × 1.10 waste = 253.0 ft³ ÷ 27 = 9.37 yd³ → one 10-yard truck
- Base: 640 ft² × 0.333 ft × 1.20 = 256 ft³ = 9.48 yd³ × 1.4 = 13.3 tons
- Rebar: 9 bars × 50 ft + 34 bars × 12 ft + about 53 ft for the apron = 911 ft; +10% laps = 1,002 ft → 51 bars of 20 ft (about 377 lb of #3)
- Joints: 4 cross joints × 12 ft + 1 center joint × 50 ft = 98 linear ft
- Material cost: 9.37 yd³ × $165 + 13.3 t × $40 ≈ $2,077
Concrete and base for common driveway sizes
Net cubic yards before waste for the main rectangle only (no edges or apron). Base tons assume 4 in of crushed stone, a 20% compaction allowance and 1.4 tons per yd³.
| Driveway (L × W) | Area | 4 in slab | 5 in slab | 6 in slab | 4 in base |
|---|---|---|---|---|---|
| 20 × 10 ft (short single) | 200 ft² | 2.47 yd³ | 3.09 yd³ | 3.70 yd³ | 4.1 t |
| 20 × 20 ft (two-car pad) | 400 ft² | 4.94 yd³ | 6.17 yd³ | 7.41 yd³ | 8.3 t |
| 24 × 24 ft (wide two-car) | 576 ft² | 7.11 yd³ | 8.89 yd³ | 10.67 yd³ | 11.9 t |
| 50 × 12 ft (single, long) | 600 ft² | 7.41 yd³ | 9.26 yd³ | 11.11 yd³ | 12.4 t |
| 100 × 12 ft (rural lane) | 1,200 ft² | 14.81 yd³ | 18.52 yd³ | 22.22 yd³ | 24.9 t |
Driveway pour tips and common mistakes
- Thickness is set by the heaviest vehicle, not the average one. If a moving truck, septic pumper or RV will ever cross it, 5–6 in is the usual choice. The city may also require a thicker apron within the right-of-way — ask for their standard detail.
- Compact the subgrade and base in lifts. Most driveway cracks trace back to soft spots underneath. Place base in 2–4 in lifts and compact each one with a plate compactor; dump-and-spread stone settles later.
- Joint depth matters as much as spacing. Tool or saw joints to at least one quarter of the slab thickness, and saw as soon as the surface can be cut without raveling — usually within the first day. Late cuts arrive after the slab has already cracked.
- Keep panels near square. A panel longer than about 1.5 times its width tends to crack across the middle. On a 12 ft drive with 10 ft joint spacing, a center joint is often added to keep panels in proportion. Many guides also cap joint spacing at about 15 ft regardless of thickness.
- Get the steel off the ground. Rebar or mesh lying on the base does nothing. Use chairs or dobies so it sits near mid-depth of the slab.
- Specify the mix for your climate. In freeze-thaw regions many specifications call for air-entrained concrete around 4,000 psi; confirm with the ready-mix plant and local requirements. Slope the surface at least 1/8 in per foot (about 1%) away from the garage.
Concrete driveway FAQ
How thick should a concrete driveway be?
Four inches is the common thickness for driveways that carry only passenger cars. Five to six inches is common practice where pickups, RVs, boats on trailers or occasional delivery trucks will park. Edges are often thickened by about 2 inches. Local code, an HOA or the city's apron detail may set a minimum, so check before you order.
How many yards of concrete do I need for a 20x20 driveway?
A 20 ft × 20 ft driveway at 4 inches is 400 × 0.333 = 133.3 cubic feet, or 4.94 cubic yards; with 10% waste, order about 5.5 yards. At 5 inches it is 6.17 cubic yards net, or about 6.8 yards with waste.
Does a concrete driveway need rebar or wire mesh?
Reinforcement does not stop concrete from cracking, but it holds cracks tight so slabs do not separate or shift. Many residential driveways use #3 bar at 18 in on center or #4 bar at 24 in, set on chairs near mid-depth; others use welded wire mesh or fibers. Follow your local code or the plans for your project.
How far apart should control joints be in a concrete driveway?
A common rule is 2 to 3 times the slab thickness in inches, expressed in feet, so a 4 in driveway gets joints every 8 to 12 ft. Cut or tool joints at least one quarter of the slab depth (1 in for a 4 in slab) and keep panels close to square.
How much gravel base goes under a concrete driveway?
Four to six inches of compacted crushed stone is typical on stable soil. A 50 ft × 12 ft driveway with a 4 in base needs 200 cubic feet in place; adding 20% for compaction gives 8.9 cubic yards, or about 12.4 tons at 1.4 tons per cubic yard.
How much does a concrete driveway cost per square foot?
Installed prices vary widely by region, access, thickness and finish. This page uses an editable placeholder of $6 to $12 per square foot for plain broom-finished concrete, so a 600 sq ft driveway would land around $3,600 to $7,200. Replace those numbers with local quotes.
How we built this calculator: results use the standard volume, area, and coverage formulas shown on this page, with typical U.S. material densities, bag yields, and waste factors that you can override. Written and checked by the YardsCalculator editorial team. Last reviewed: October 2026.