🧱 Concrete Driveway Calculator

How to Measure a Driveway for Concrete

Length × width × thickness, with every measurement in feet, then divide by 27. The only step people miss is that last division — a cubic yard is 27 cubic feet, not 3. A 20 × 20 ft driveway at 5 in is 400 sq ft, 166.7 cubic feet, and 6.17 cubic yards.

Measuring a driveway that is not a rectangle

Most driveways are not. Break the shape into rectangles at every corner, work each one out separately, and add them up — the same method as any irregular slab. Three pieces cover almost every layout:

• The run. Curb or garage door to the far end, times the width.
• The apron. The flare where the drive meets the road is usually wider than the run. Measure it as its own rectangle at its average width.
• The parking pad or turnaround. Another rectangle alongside the run. Do not double-count the overlap where they meet.

Our square footage calculator handles the splitting if the shape is awkward; bring the total back here with your thickness.

Do not forget the thickness

Thickness moves the number more than anything else, because it multiplies the whole area. Going from 4 in to 5 in on that same 20 × 20 ft driveway takes it from 4.94 to 6.17 cubic yards — a quarter more concrete for one extra inch.

Concrete Driveway Size Chart

Cubic yards for common driveway sizes at each standard thickness, before overage. These are the figures the calculator above returns; use it for any size not listed.

All figures in cubic yards, before waste. Add about 10% for subgrade variation — a driveway is poured on ground, and ground is never as flat as it looks. Ready-mix is sold in quarter-yard increments, so round up to the next quarter after adding overage.

Concrete Driveway Thickness Guide

5 Inches — Standard Residential

Suitable for standard passenger cars and light daily use. This is the minimum recommended thickness for any concrete driveway.

6 Inches — Heavy Vehicles

Required if you park trucks, SUVs, RVs, or trailers on your driveway. The extra inch adds significant load-bearing capacity.

Gravel Sub-Base

Always add 4-6 inches of compacted gravel base underneath the concrete slab. This provides drainage, prevents shifting, and reduces cracking.

Concrete Mix Strength

Use 4,000 PSI concrete mix for driveways (not the standard 3,000 PSI). The higher strength handles vehicle weight and freeze-thaw cycles much better.

Driveway Cost Breakdown

Driveway Size	DIY Cost	Professional Cost
Single-Car (10×20 ft)	$800 – $1,500	$2,000 – $4,000
Double-Car (20×20 ft)	$1,500 – $2,800	$4,000 – $8,000

What's included in these estimates:

• Excavation and site preparation
• Compacted gravel base (4-6 inches)
• Forming and rebar/wire mesh
• Concrete material and delivery
• Finishing, curing compound, and sealer

Driveway Pro Tips & Mistakes to Avoid

Pro Tips

• Match thickness to the load. 4 inches handles passenger cars; go to 5–6 inches for trucks, RVs, or heavy delivery vehicles, and thicken the edges where wheels roll on and off.
• Use rebar, not just mesh. A #4 rebar grid gives a driveway the load capacity that fiber or wire mesh alone can't.
• Spec the right mix. Use 3,500–4,000 PSI, and air-entrained concrete in freeze-thaw climates for scaling resistance.
• Plan your joints. Space control joints (in feet) no more than about 2–2.5× the slab thickness in inches, and isolate the slab at the garage slab and street apron.

Mistakes to Avoid

• Parking too soon. Wait the full 28 days before driving on new concrete; early loads cause cracks.
• De-icing salts the first winter. Fresh concrete is vulnerable — skip chemical de-icers for the first year and use sand for traction.
• No slope. Pitch the driveway about 1–2% away from the garage so water and snowmelt drain off.

Frequently Asked Questions

How thick should a concrete driveway be?

A minimum of 5 inches for standard residential cars. Use 6 inches if you have trucks, SUVs, or RVs that will park on the driveway regularly.

How long before I can drive on new concrete?

Wait a minimum of 7 days before driving on new concrete. Full curing takes approximately 30 days — avoid heavy loads and sharp turns during this period.

Do I need rebar in a driveway?

Yes. Use #4 rebar placed on an 18-inch grid pattern, or 6×6 welded wire mesh (WWM) throughout the slab. Reinforcement prevents cracking from vehicle weight and ground movement.

Concrete vs asphalt driveway?

Concrete: $8-18 per sq ft installed, lasts 25-30 years with minimal maintenance. Handles heat better and won't soften.
Asphalt: $3-7 per sq ft installed, lasts 15-20 years but requires resealing every 3-5 years. Can soften in extreme heat.

How much does a concrete driveway cost?

Expect $6–$12 per square foot installed for a plain broom finish, and $12–$20+ for stamped or colored concrete. A standard 12 × 50 ft driveway runs roughly $4,000–$7,000. DIY materials alone are around $3–$5 per square foot.

What PSI concrete should a driveway be?

4,000 PSI for a driveway, and 4,000–4,500 in freeze-thaw regions where you also want air entrainment. Don't use a 3,000 PSI patio mix — vehicle loads and de-icing salts are considerably harder on concrete than foot traffic.

How far apart should driveway control joints be?

In feet, no more than 2–3× the slab thickness in inches — so a 4-inch driveway needs joints every 8–12 feet, and a 5-inch every 10–15. Cut them at least a quarter of the slab depth, within 6–12 hours of the pour.

Does a concrete driveway need a gravel base?

Yes. Lay 4–6 inches of compacted crushed stone under the slab. It spreads the load, drains water away from the underside, and stops frost heave. Pouring on bare soil is the most common cause of a cracked driveway.

Should a driveway slope for drainage?

Yes — a minimum of 1/8 inch per foot, and 1/4 inch per foot is better. Always slope away from the garage and the house. Water pooling on a slab is what drives freeze-thaw damage and surface scaling.

How long does a concrete driveway last?

25–40 years with a proper base, adequate thickness, and correct jointing. Sealing every 2–3 years helps considerably in climates that use de-icing salt, which is the main chemical enemy of a concrete surface.

Should I use wire mesh or rebar in a driveway?

#3 or #4 rebar on a 18–24 inch grid is the better choice for a driveway. Welded wire mesh works but is notoriously hard to keep at mid-slab depth once people walk on it during the pour. Whichever you use, it must sit on chairs — steel lying on the ground does nothing at all.

How wide should a driveway be?

10–12 feet for a single lane and 20–24 feet for two cars side by side. Add 2–3 feet on curves, since vehicles track wider through a turn. Allow at least 20 feet of depth in front of a garage door so a parked car clears the sidewalk.

Why is my new driveway cracking?

Some hairline cracking is normal. Structural cracking usually traces to one of four things: an uncompacted base, control joints spaced too far apart, too much water in the mix, or a slab poured too thin for the vehicles using it. Cracks wider than about 1/8 inch, or with one side sitting higher than the other, indicate a base problem rather than a surface one.

Do I need an expansion joint where the driveway meets the garage?

Yes — an isolation joint, using compressible joint filler. The driveway and the garage slab move independently with temperature and soil moisture, and tying them rigidly together cracks one or both. The same applies where the drive meets a sidewalk or foundation wall.