Volume formula
length (ft) × width (ft) × thickness (in) ÷ 12 ÷ 27 = yd³
Example: 20 × 12 × 5 ÷ 12 ÷ 27 = 3.09 yd³ net.
Concrete planning estimate
Concrete Driveway Calculator
Estimate concrete volume, bag count, gravel base, rebar, and rough material cost for a concrete driveway. Driveways need heavier concrete and more reinforcement than patios — this calculator uses the correct driveway defaults.
What this driveway calculator estimates
The calculator uses driveway-specific defaults: 5 in thickness, rebar grid reinforcement, 10% waste factor, and 4000 psi (M300) concrete — the standard for residential driveways.
- Concrete volume in cubic yards for ready-mix ordering.
- Bag count if you choose to use bagged concrete.
- Compacted gravel base volume and weight (6 in default).
- Rebar stick count and spacing for grid reinforcement.
- Form board count from driveway perimeter.
- Rough material cost range for concrete, gravel, forms, and rebar.
Driveway concrete formula
Driveway estimates use the same slab volume formula with driveway-standard inputs.
Driveway waste factor
Use 10% waste for driveways. Driveways have less margin for running short than patios, and subgrade variation is common.
Why 4000 psi?
4000 psi concrete resists vehicle loads and freeze-thaw damage better than 3000 psi. Most DOT and residential codes require at least 4000 psi for exterior vehicle slabs.
Common driveway size estimates
Pre-calculated for 5 in thickness, M300 concrete, 10% waste, and 6 in gravel base.
| Driveway size | Net yd³ | Ordered yd³ | 80 lb bags | Ordering |
|---|---|---|---|---|
| 10 × 20 × 5 in (single) | 3.09 | 3.40 | 155 | Ready-mix recommended |
| 12 × 20 × 5 in (single) | 3.70 | 4.07 | 185 | Ready-mix recommended |
| 16 × 30 × 5 in (single long) | 7.41 | 8.15 | 371 | Ready-mix required |
| 20 × 20 × 5 in (two-car) | 6.17 | 6.79 | 309 | Ready-mix required |
| 24 × 24 × 5 in (two-car wide) | 8.89 | 9.78 | 445 | Ready-mix required |
Driveway ordering checklist
Driveways are rarely a DIY bag-mix project. Plan for ready-mix, proper subbase, and rebar before ordering.
- 4000 psi (M300) ready-mix concrete with air entrainment in freeze-thaw climates.
- Compacted road base or gravel base, 6 in minimum.
- Rebar grid: #5 rebar at 18 in spacing is a common residential standard.
- Form boards, pins, and duplex nails for straight edges.
- Control joints every 10–12 ft across the driveway.
- Not included: excavation, labor, delivery, permits, vapor barrier, or sealer.
Concrete driveway calculator FAQ
How much concrete does a standard driveway need?
A standard two-car driveway (20 ft × 20 ft × 5 in) needs about 6.17 yd³ net and about 6.79 yd³ with 10% waste. Ready-mix is strongly recommended at this volume.
How thick should a concrete driveway be?
Most residential driveways for passenger vehicles are 5 in thick. Areas where heavy trucks or RVs will park benefit from 6 in. Always use a compacted base and rebar grid for driveways.
Should I use 3000 or 4000 psi concrete for a driveway?
4000 psi (about M300) is the standard choice for driveways, especially in freeze-thaw climates. The extra strength and durability justify the modest cost difference.
Do I need rebar in a concrete driveway?
Yes — a rebar grid (#5 rebar at 18 in spacing is common) significantly reduces cracking and slab movement. Wire mesh alone is not sufficient for vehicle loads in most conditions.
How do I prevent driveway cracks?
Cut control joints every 10–12 ft, use proper subbase, maintain minimum 5 in thickness, cure properly, and seal the surface annually. Even well-built driveways develop some hairline cracks over time.
How much waste factor for a driveway?
Use 10% for driveways. The combination of form variance, subgrade irregularity, and the risk of running short justifies the higher waste factor versus a simple patio.
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Planning estimates only
These are rough material estimates for planning purposes. They are not purchasing guarantees, engineering designs, or code compliance guidance. Confirm local code, subbase requirements, rebar sizing, slab thickness, and supplier yields with a qualified professional before ordering concrete for a driveway.