How Much Concrete Do I Need for a Patio? (Complete Guide)

The Quick Answer

For a standard 4-inch thick patio, you need approximately 1.23 cubic yards of concrete per 100 square feet. A typical 10x10 patio needs about 1.23 cubic yards, a 12x12 patio needs about 1.78 cubic yards, and a 12x16 patio needs about 2.37 cubic yards.

Use our free concrete calculator above to get an exact number based on your specific dimensions. The calculator accounts for slab thickness, shape, and even estimates cost and bag counts.

How to Calculate Concrete for a Patio

The formula is simple: Length (ft) × Width (ft) × Thickness (ft) ÷ 27 = Cubic Yards. The division by 27 converts cubic feet to cubic yards, which is how concrete is sold.

For example, a 12x16 patio that is 4 inches thick: 12 × 16 × 0.333 ÷ 27 = 2.37 cubic yards. Always round up and add 5-10% extra for waste, spillage, and uneven ground.

If using bagged concrete instead of ready-mix, know that one 80-pound bag yields about 0.6 cubic feet of mixed concrete. For our 12x16 example, you would need approximately 107 bags — which makes ready-mix delivery much more practical for anything over 1 cubic yard.

Common Patio Sizes and Concrete Needed

8×10 patio (80 sq ft): 0.99 cubic yards at 4" thick — approximately 45 bags of 80-lb mix or $120-$160 for ready-mix delivery.

10×10 patio (100 sq ft): 1.23 cubic yards at 4" thick — approximately 56 bags or $150-$200 for ready-mix.

10×12 patio (120 sq ft): 1.48 cubic yards at 4" thick — approximately 67 bags or $180-$240 for ready-mix.

12×12 patio (144 sq ft): 1.78 cubic yards at 4" thick — approximately 80 bags or $215-$285 for ready-mix.

12×16 patio (192 sq ft): 2.37 cubic yards at 4" thick — approximately 107 bags or $285-$380 for ready-mix.

16×20 patio (320 sq ft): 3.95 cubic yards at 4" thick — ready-mix delivery strongly recommended at $475-$630.

How Thick Should a Concrete Patio Be?

Standard residential patios should be 4 inches thick. This is the minimum recommended by most building codes and provides adequate strength for foot traffic, patio furniture, and light use.

If the patio will support heavy items like a hot tub, outdoor kitchen, or is used as a parking pad, increase thickness to 5-6 inches. Vehicle traffic requires a minimum of 6 inches with reinforcement.

The sub-base is equally important. Compact 4-6 inches of gravel before pouring to ensure proper drainage and prevent cracking from ground movement. In cold climates, extend the gravel base deeper to protect against frost heave.

Cost Breakdown for a Concrete Patio

Ready-mix concrete costs $120-$160 per cubic yard delivered. For a 12x12 patio (1.78 cu yd), the concrete alone costs approximately $215-$285.

Additional material costs include: gravel base ($25-$50), forms and stakes ($30-$80), rebar or wire mesh ($50-$100), and concrete sealer ($20-$40). Total materials for a DIY 12x12 patio run $340-$555.

Professional installation adds $4-$8 per square foot for labor. A professionally poured 12x12 patio typically costs $1,000-$2,200 total, depending on finishing (broom finish vs. stamped or colored concrete).

Tips for a Successful Patio Pour

Order 10% more concrete than calculated. Running short during a pour is extremely costly — you cannot easily add concrete to a partially cured slab without creating a cold joint.

Check the weather forecast. Ideal pouring temperature is 50-80°F. Avoid pouring in direct hot sun (concrete cures too fast) or when rain is expected within 24 hours.

Have enough help on hand. Concrete waits for no one — once the truck arrives, you typically have 60-90 minutes to place, screed, and finish the concrete before it becomes unworkable.

Cure the concrete properly. Keep the surface moist for at least 7 days by covering with plastic sheeting or spraying water daily. Proper curing develops 50% more strength than uncured concrete.