How to Estimate Concrete Cost in 2026: Cubic Yards, PSI, and What Contractors Charge

Most homeowners have no idea whether a concrete quote is fair. A contractor hands you a number, you have nothing to check it against, and you sign. The problem is that you cannot tell if the price covers the right amount of concrete — or the right kind.

That uncertainty is expensive. Ready-mix is quoted in cubic yards, sold in fractional yards, and carries short-load fees that can quietly double the per-yard price on a small job. None of this is explained upfront, so the only way to protect yourself is to run the numbers yourself before anyone shows up with a truck.

The good news: the math is simple, and once you know it, you can sanity-check any quote in about two minutes. You can calculate your cubic yards and cost range before calling suppliers and walk into the conversation already knowing what the job should cost.

Start with cubic yards

Concrete is sold by the cubic yard, so every estimate starts by converting your slab into that unit. Measure length and width in feet, and thickness in inches. Convert thickness to feet by dividing by 12.

Multiply the three numbers together to get cubic feet. Then divide by 27 — there are 27 cubic feet in a cubic yard. That divide-by-27 step is the one most people forget.

For a 20-foot by 20-foot patio at 4 inches thick: 20 × 20 × (4 ÷ 12) = 133 cubic feet. Divide by 27 and you get about 4.9 cubic yards. That is your raw volume, before waste.

Always add 10% for waste

Never order your exact calculated volume. Subgrade is never perfectly level, forms flex, and some concrete stays stuck in the truck and chute. The industry standard is a 10% waste allowance.

So multiply your volume by 1.10. Our 4.9-yard patio becomes about 5.4 yards ordered. Skipping this step is how people run short mid-pour — and a shortfall creates a cold joint, a permanent weak seam where fresh concrete meets concrete that has already started to set.

Choosing the right PSI

PSI is the compressive strength of the mix, and it directly affects both durability and price. Picking the right one matters more than most people realize.

Use 2,500 PSI only for light-duty walkways. 3,000 PSI is the standard for residential flatwork — patios, basement floors, and shed pads. Step up to 4,000 PSI for driveways and garage slabs, especially anywhere with freeze-thaw cycles or vehicle traffic. Reserve 5,000 PSI for structural and industrial work.

Higher strength means more cement, so each step up adds roughly $10–$20 per cubic yard. For a driveway, paying for 4,000 PSI is cheap insurance against cracking and surface scaling.

Ready-mix versus bags: the one-yard rule

The break-even point between bagged concrete and a ready-mix truck sits at about one cubic yard. Below one yard, bags usually win once you factor in delivery fees. Above one yard, ready-mix is both cheaper per yard and far less work.

One 80 lb bag yields about 0.60 cubic feet, so you need roughly 45 bags per cubic yard. Mixing 45 bags by hand for a single yard is brutal — and once you cross two or three yards, doing it by bag is no longer realistic.

2026 price ranges

In 2026, ready-mix runs roughly $120–$180 per cubic yard delivered, depending on strength and region. Standard 3,000 PSI residential mix averages around $138 per yard. Budget toward the high end if you are in a high-cost metro or ordering a small load.

If you want concrete installed rather than just delivered, expect about $6–$13 per square foot for flatwork, including labor, forming, and finishing. Labor alone typically lands at $5–$8 per square foot. A standard 400-square-foot slab therefore costs somewhere between $2,600 and $5,200 installed.

Put it together

Run your dimensions through the cubic-yard formula, add 10% waste, pick a PSI that matches the use, and decide between bags and ready-mix using the one-yard rule. Add a short-load fee if your order is under three yards, and add labor if you are hiring it out.

Do that, and you can compare any contractor quote line by line instead of guessing. These figures are estimates only — always get three written contractor quotes before ordering, since local pricing, site conditions, and delivery distance all shift the final number.