Concrete Cost & Yardage Calculator

Q: How do I calculate how many yards of concrete I need?

Multiply length by width by thickness (all in feet) and divide by 27 to convert cubic feet to cubic yards.

Q: How much does it cost to pour a concrete slab?

A fully installed standard slab typically runs $6-$12 per square foot, so a 200 sq ft patio runs roughly $1,200-$2,400 installed.

Find exactly how many cubic yards of concrete you need for any slab, footing, or pad — plus a ready-mix delivery and fully-installed cost estimate.

Length (feet)

Width (feet)

Slab Thickness

Pricing Method

Concrete Needed & Estimated Cost

Typical range: $0 – $0

Slab Area

0 sq ft

Cubic Yards (+10%)

80lb Bags Equiv.

How to Calculate Concrete Yardage

Concrete is ordered by the cubic yard, not by the bag, once a project gets bigger than a few post holes. The formula is straightforward: Length (ft) × Width (ft) × Thickness (ft) ÷ 27 = Cubic Yards. The trickiest part is the thickness — it's always listed in inches but the formula needs feet, so divide your thickness in inches by 12 first. A 20×10 ft pad at 6 inches thick works out to 20 × 10 × 0.5 ÷ 27 = 3.7 cubic yards.

Always add a 5–10% waste buffer on top of the raw math — sub-base isn't perfectly flat, forms shift slightly, and ready-mix trucks round up to the nearest quarter yard anyway. This calculator builds that 10% buffer in automatically.

Ready-Mix vs. Installed Cost: What's the Real Difference?

Pricing Method	Typical Cost	What's Included
Ready-Mix Delivered	$150 – $200 / cubic yard	Truck delivery of mixed concrete only. You supply forms, rebar/mesh, and labor.
Fully Installed	$6 – $12 / sq ft	Excavation, forms, rebar/mesh, pour, finishing, and cleanup — typical for a standard 4"–6" slab.

Decorative finishes (stamped, colored, exposed aggregate) typically add $2–$6 per sq ft on top of installed pricing. Figures are national averages and vary by region — always confirm with local suppliers.

Pro Tip: Don't Order Right at the Line Always round your yardage order up, not down. Ready-mix trucks charge a "short load" fee (often $50–$100+) if you order less than a full or three-quarter truckload, and running short mid-pour means a costly rush second delivery before your first load sets up.

Frequently Asked Questions

How do I calculate how many yards of concrete I need?

Multiply length × width × thickness (all in feet) and divide by 27 to convert cubic feet to cubic yards. For a 4-inch slab, thickness in feet is 4 ÷ 12 = 0.33 ft.

How much does a cubic yard of concrete cost?

Ready-mix delivered concrete typically costs $150–$200 per cubic yard as of 2026, before any pump truck, labor, or finishing costs are added.

How much does it cost to pour a concrete slab?

A fully installed standard slab (excavation, forms, rebar, pour, and finish) typically runs $6–$12 per square foot, so a 200 sq ft patio runs roughly $1,200–$2,400 installed.

Should I use bags or ready-mix for my project?

As a rule of thumb, anything under 1 cubic yard (about 45 bags of 80lb mix) is usually cheaper and easier to mix yourself with bags. Use our Concrete Bag Calculator for the exact bag count. Beyond 1 yard, ready-mix delivery is almost always faster and more cost-effective.

How thick should a concrete driveway be?

4 inches is the minimum for passenger vehicles; 5–6 inches is recommended for driveways that will see trucks, RVs, or heavy regular use.

🧱 Concrete Cost & Yardage Calculator