Concrete Calculator

• Ready-mix runs $129.89–$190.83 per yard; bags cost $258–$371 per equivalent yard in material alone, roughly double.
• Orders under 4-5 yards trigger a short-load fee of $40–$150 that can double your effective per-yard cost on small pours.
• A 12×10 patio at 4 inches installed: $932–$1,751. A 20×20 driveway at 5 inches: $3,282–$6,096.
• 10% overage (ACI 304R standard) is the minimum buffer. Running short mid-pour creates a cold joint, a permanent structural weak point.
• Full cure takes 28 days. Parking on a slab before day 7 risks cracking that only a full replacement fixes.

Prices below come from the BLS Producer Price Index for Ready-Mix Concrete and the PPI for Prepackaged Concrete Mixes, updated monthly. These track what producers charge, not what you'll pay at the truck.

Your delivered price adds the supplier's margin, fuel surcharge, and any short-load penalty. Labor rates reflect BLS wage data for cement masons and concrete finishers.

This concrete calculator sizes your pour and prices the material. It doesn't include excavation ($1–$5 per sq ft), gravel base ($0.80–$1.50 per sq ft), forms, reinforcement, or permits ($50–$400).

For irregular shapes, stepped footings, or commercial work, get a site-specific quote from your batch plant. Some calculators break concrete into cement, sand, and aggregate quantities; that matters for raw-material mixing, not for ready-mix or bagged concrete.

The math on paper: length × width × depth in feet, divided by 27, plus 10% (ACI 304R standard). For a 12×10-foot patio at 4 inches: 12 × 10 × 0.333 = 39.96 cubic feet ÷ 27 = 1.48 yards, plus 10% overage (ACI 304R standard) = 1.63 yards (standard ACI 304R allowance). Material at $129.89–$190.83 per yard comes to $212–$311. Labor adds $6–$12 per square foot.

On 120 square feet that's $720–$1,440, putting the installed total at $932–$1,751.

The calculator above handles this math; the table below shows what it produces for common projects.

A real pour, priced out: A homeowner in Phoenix scheduling a 20×20-foot driveway pour in early October orders 7 yards of 4,000 PSI from a local batch plant. Material: $909–$1,336.

The crew quotes $8 per square foot for grade, pour, and broom finish on a flat lot with direct chute access. That's $3,200 in labor, putting the job at $4,100–$4,500.

If this driveway needs to handle a loaded pickup or RV, set the thickness to 6 inches in the calculator above. Yardage jumps to 8.15, and material alone rises to $1,059–$1,555.

These totals are material plus labor. Starting from bare dirt adds site prep: excavation at $1–$5 per square foot plus 4-6 inches of compacted gravel at $0.80–$1.50 per square foot.

On a 400-square-foot driveway, that site prep runs $720–$2,600. Your next step: call three local batch plants for a delivered price per yard.

Order size and short-load fees Batch plants set a truck minimum of 4-8 yards. Order less and you pay $40–$150 flat, or $15–$75 per yard on top of material.

On a 2-yard order with a $100 short-load fee, your effective cost per yard jumps by $50. Below half a yard, bags sidestep this entirely.

Mix strength Standard residential is 3,000 PSI. Driveways, garage floors, and slabs in freeze-thaw zones should be 4,000 PSI or higher. The upgrade runs $15–$40 per yard. On a 7-yard driveway pour, that's $105–$280 for a slab that won't crack under load in year three.

Finish treatment A broom finish falls within the standard $6–$12 per square foot labor rate. Stamped, stained, or exposed-aggregate finishes run $9–$30 per square foot installed. On a 400-square-foot driveway, that's $3,600–$12,000 for decorative versus $2,400–$4,800 for plain.

Region West Coast and Northeast metros run 20–40% above Midwest, per BEA Regional Price Parities and Southern prices. The same 7-yard pour that costs $909 in material in Phoenix could run $1,090–$1,270 in Seattle or Boston. Your batch plant quote is the final check on regional pricing.

Truck access If the truck can chute directly to your forms, there's no added cost. A fence, slope, or long run between the street and the pour site means a pump truck, which adds a separate line item to the job. Ask the batch plant about access before you order.

Timing Material prices track producer costs and don't swing much by season. Contractor labor runs 10–20% lower in shoulder months (USDA ERS seasonal contractor data) when crews aren't fully booked.

The cheapest pour window: October or March. Temperatures stay between 50–90°F (ACI 305R hot-weather concrete range), demand drops, and crews negotiate.

Most concrete failures aren't bad luck. They're skipped steps that cost double because the only fix is demolition and repour.

Under-ordering by even half a yard The truck runs dry mid-pour. A cold joint forms where fresh concrete meets set concrete, creating a permanent crack line and structural weak point. Emergency short-load top-offs cost 2–3 times the normal rate (ACI 304R short-load fee guidance).

The 10% overage (ACI 304R standard) the calculator builds in exists for this reason. Leftover concrete is always cheaper than a cold joint.

Skipping the gravel base The base costs $0.80–$1.50 per square foot to do right. Skipping it is the number-one cause of driveway cracking and settling within 2-3 years.

The fix: demo at $1–$5 per square foot plus a full repour. On a 400-square-foot driveway, that's $320–$600 saved now versus a $2,800–$6,100 redo later.

Four inches under a truck A 4-inch slab handles patios and walkways. A loaded pickup or RV cracks it within two years. Driveways need 5-6 inches.

The extra depth on a 20×20 pour is about 2.7 yards, roughly $350–$520. Skipping it means a full tearout when the slab fails under load.

Finishing on bleed water Troweling before surface water evaporates traps moisture under the finish. The result: scaling, spalling, and delamination within the first winter. This is a crew error, not a material defect. Repair means grinding, an overlay, or full replacement.

No control joints Concrete cracks. Joints direct those cracks into straight, planned lines. Without them, cracks run random and diagonal across the slab.

Space joints 2-3 times the slab thickness in feet: 8-12 feet apart on a 4-inch slab. Cutting them during the pour costs almost nothing; random cracks afterward are permanent.

Driving on it too soon Concrete reaches about 70% of design strength (ACI 318) of design strength at 7 days (ACI 318), full design strength at 28. Parking a car at day 3 or a heavy truck at day 10 risks surface damage or structural cracking. There's no cosmetic fix for a cracked slab.

Pouring below 40°F without protection (ACI 306R cold-weather concrete threshold) Fresh concrete that freezes before curing won't reach design strength. It may look fine for months, then spall and crumble in the first freeze-thaw cycle. Heated blankets and hot water add cost to winter pours, but less than a slab that fails at 18 months.

An 80-lb bag yields 0.6 cubic feet. One cubic yard is 27 cubic feet, so you need 45 bags to match a single yard from a truck.

At $5.74–$8.25 per bag, that's $258–$371 per yard in bags, roughly double the $129.89–$190.83 per yard for ready-mix. Bags win only when the truck's short-load fee ($40–$150 on orders under 4-5 yards) makes delivery more expensive than the bag premium.

That crossover sits around half a yard, about 22 bags of 80-lb mix. Below that, bags are cheaper and you control the pace; above it, a truck saves money and the crew finishes faster.

The 60-lb bags at $4.68–$7.17 each require 60 per yard, $281–$430 total. Easier on your back, but more expensive per yard. If you can handle 80 pounds, buy those.

When to pour it yourself and when to hire a crew

Concrete sets in 60-90 minutes. A small patio at 1-2 yards is doable for a homeowner with a helper. The savings: $932–$1,751 installed versus $212–$311 in DIY material. That's $720–$1,440 in labor you keep.

A 400-square-foot driveway is a different animal. You need to screed, float, edge, and broom-finish 7 yards before it kicks. That takes a 4-5 person crew working fast for 3-4 hours.

A homeowner team that falls behind ends up with trowel marks, low spots, or a pour that sets before finishing. On a 20×20 driveway, you have 45–60 minutes of workable time before the mix stiffens. Demo and repour doubles the cost.

If you're past 3-4 yards and haven't done it before, hire the crew. Budget $50–$90 per day for a mixer rental on bag routes past 10-15 bags.

A contractor's installed price includes material, labor, overhead, and profit. Standard markup: 15–25% overhead plus 10–15% profit (ACI 305R contractor markup norms) on direct costs.

If the calculator shows $882–$1,296 material and $2,400–$4,800 labor for a 20×20 driveway ($3,282–$6,096 direct), a fair bid lands around $4,100–$8,530 after 25–40% combined markup (ACI 305R).

A bid well below that floor means something's being cut: thinner pour, lower PSI, skipped gravel base, or no reinforcement.

Every shortcut shows up as cracking and settling 1-3 years out, after the savings are spent.

Walk away if you see any of these:

• More than 30% deposit demanded upfront (industry norm is 10–30%, per CFPB contractor guidance).
• Cash-only pricing, which usually signals no insurance.
• No proof of license or insurance when asked.
• No written contract naming PSI, thickness, reinforcement type, and joint spacing.
• A bid well below every other quote with vague specs like "we use good concrete."