How to estimate concrete cost
- Work out the volume. Length × width × thickness gives the cubic yards of concrete. Add 5–10% for waste and uneven ground.
- Price the concrete. Multiply the cubic yards by your supplier's price per yard. Add any delivery or short-load fee — many plants charge one for orders under a set number of yards.
- Compare bags. For small pours, multiply the number of 80 lb bags by the bag price. Remember mixer rental and your time.
- Add the rest of the job. Gravel base, forms, rebar or wire mesh, finishing and labor usually cost more than the concrete itself on a contractor-built slab. Enter them per square foot to see the full cost.
Worked example: a 20 × 12 ft driveway pad
At 4 inches thick, a 20 × 12 ft pad is 240 sq ft and 2.96 cubic yards — 3.26 yards with 10% waste. At an example price of $165 per yard, the ready-mix costs about $538. The same pour in 80 lb bags needs 147 bags; at $6.50 each that is about $956, before mixer rental. That is why ready-mix almost always wins once a job passes about one cubic yard.
Ready-mix or bags?
| Ready-mix truck | Premixed bags | |
|---|---|---|
| Best for | Slabs, driveways, footings over about 1 yd³ | Post holes, small pads, repairs |
| Pricing | Per cubic yard, plus short-load or delivery fees on small orders | Per bag; 45 bags of 80 lb mix make one cubic yard |
| Labor | Concrete arrives mixed; you need a crew ready to place it | You mix every bag by hand or with a rented mixer |
| Consistency | One batch, uniform strength | Varies with water added to each batch |
What changes the price
- Thickness. Going from 4 to 6 inches adds 50% more concrete.
- Mix strength and additives. Higher-strength mixes, fiber, color, accelerators and cold-weather additives all add to the price per yard.
- Access. If the truck can't reach the forms, a pump or buggies add cost.
- Finish. Broom finish is the cheapest; stamped or exposed-aggregate finishes cost considerably more per square foot.
- Site prep. Excavation, a compacted gravel base and forms are often a large share of a contractor's quote.
Plan the whole job
Size the stone underneath with the gravel calculator, get exact bag counts with the concrete bag calculator, and check footings with the concrete footing calculator. Our slab thickness guide covers how thick each type of slab should be.
Frequently asked questions
How much does a yard of concrete cost?
Ready-mix prices vary by region, mix and order size, so get a quote from your local plant. Enter that price per yard above. Small orders often carry a short-load fee, which can make a one-yard order cost noticeably more per yard.
How much does a 10×10 concrete slab cost?
A 10 × 10 ft slab at 4 inches needs about 1.36 cubic yards with waste. Multiply that by your local price per yard for the material cost, then add forms, base, reinforcement and labor if a contractor is pouring it.
Is it cheaper to pour concrete yourself?
Doing the work yourself saves labor, which is often the largest part of a contractor's price. But larger slabs need several people working quickly, and finishing mistakes are hard to fix once the concrete sets.
Is it cheaper to buy bags or ready-mix?
For pours under about one cubic yard, bags are usually more practical. Above that, ready-mix is normally cheaper per yard and far less work, even with a delivery fee.
How do I estimate concrete cost per square foot?
Divide the total cost by the area. The calculator shows this as total cost per area, including any labor and extras you enter.