Concrete Cost Calculator
This concrete cost calculator turns the size of a slab, patio, driveway pad, round column or a volume you already know into cubic yards, then multiplies by the prices you enter. Choose ready-mix (a price per cubic yard, with delivery, short-load and other fees) or bagged mix (a price per bag in 80, 60 or 50 lb), then add labor per square foot and other materials. It quotes no prices of its own: every price is yours.
Quick answer: cost = volume × (1 + allowance) × your price, plus fees, labor and other materials. A 10 × 12 ft slab 4 in thick is 40 ft³. With a 10% allowance that is 44 ft³, or 1.6296 yd³. At an example price of $100 per cubic yard that is $162.96 before fees. Replace the example with a written quote from your supplier.
The cost of a concrete pour is the volume, with your allowance, times the price you are quoted, plus any fees, labor and other materials. Find the volume in cubic feet (length × width × thickness in inches ÷ 12), add the allowance, divide by 27 for cubic yards, then multiply by your price per cubic yard. For bagged mix, divide the cubic feet by the yield printed on the bag, round up and multiply by your price per bag.
Example: a 10 × 12 ft slab, 4 in thick, is 40 ft³. With a 10% allowance that is 44 ft³, or 1.6296 yd³. At an example price of $100 per yd³ the concrete is $162.96. Add an example $50 delivery fee, a $75 short-load fee, $240 of labor and $100 of other materials and the total is $627.96. Those prices are round illustrations, not quotes.
Method
How this calculator works
The volume math is exact. The prices are not ours to know: they vary by region, supplier, date and order size, so you type them in and the answer is only as good as your quotes.
Volume and allowance
The pour volume comes from the shape you pick. A slab is length × width × thickness, with the thickness in inches divided by 12. A round column is π × (diameter ÷ 2)² × height. Or you can type a volume you already have. The allowance is applied once to that volume and the result is divided by 27 for cubic yards. In the metric view the volume stays in cubic meters and the price is per cubic meter.
Volume = Length × Width × (Thickness ÷ 12)Round column: Volume = π × (Diameter ÷ 2)² × HeightVolume to price (yd³) = Volume × (1 + Allowance ÷ 100) ÷ 27Ready-mix or bags
Ready-mix is the volume with allowance times your price per cubic yard. The volume is not rounded up to a quarter yard, because suppliers set their own increments and minimums. Bagged mix is the volume in cubic feet divided by the yield per bag, rounded up, times your price per bag. The yields (0.60, 0.45 and 0.375 ft³ for 80, 60 and 50 lb bags) come from one product's data sheet, QUIKRETE Concrete Mix #1101, so check the number on your own bag.
Ready-mix material = Volume (yd³) × Price per yd³Bags = round up (Volume in ft³ ÷ Yield per bag)Bagged material = Bags × Price per bagFees, labor and other materials
Delivery, other fees (pump, fuel, washout) and other materials (rebar, forms, base) are flat amounts you type. The short-load fee is added only when you enter a minimum order and the volume with allowance is below it. Labor is a rate per square foot (square meter in the metric view) charged on the slab area, so it applies to slabs only. Each money line is rounded to cents, so the breakdown adds up to the total on screen.
Total = Material + Delivery + Short-load fee (if below the minimum) + Other fees + Labor + Other materialsCost per ft² = Total ÷ Slab areaCost per yd³ (all-in) = Total ÷ Volume with allowanceThe allowance
Extra volume covers spillage, an uneven subgrade and bowed forms. The calculator starts at 10%, a common convention for a simple slab, and accepts 0 to 25%. Estimators often use more for curved, stepped or congested pours. It is a starting point you change, not a rule, and with 0% the calculator warns that any spillage will leave you short.
Volume to price = Volume × (1 + Allowance ÷ 100)Bag yields used for the bag count
| Bag size | Yield per bag | Bags for the 44 ft³ example |
|---|---|---|
| 80 lb bag | 0.60 ft³ | 74 |
| 60 lb bag | 0.45 ft³ | 98 |
| 50 lb bag | 0.375 ft³ | 118 |
What each field does
| Field | What to enter |
|---|---|
| Concrete volume | Slab / patio (length, width and thickness), Column / round (diameter and height), or I know the volume. |
| Length and Width | The slab footprint, in feet and inches in the US view or meters and centimeters in the metric view. |
| Thickness | Slab depth. A plain number is inches (centimeters in the metric view). |
| Diameter and Height | For a column. The diameter is a plain number of inches (centimeters in metric). |
| Volume | For I know the volume: cubic yards (cubic meters in metric), before the allowance. |
| Allowance | 0 to 25%, starting at 10%. Your call: 10% is a common starting point, not a rule. |
| Pricing | Ready-mix (price per cubic yard) or Bagged mix (price per bag). Fill in the prices below that match. |
| Ready-mix price | Your supplier's price per cubic yard. The 100 in the field is an example price, and a warning shows while it is unchanged. In the metric view the example is 130 per cubic meter. |
| Delivery fee | Ready-mix only. A flat amount. |
| Minimum order | Ready-mix only, in cubic yards. Empty means no short-load fee. |
| Short-load fee | Ready-mix only. Added only when the volume with allowance is below the minimum order. |
| Other fees | Ready-mix only. Pump, fuel, washout or anything else on the quote. |
| Bag size | Bagged mix only: 80, 60 or 50 lb. The yield comes from one data sheet. |
| Price per bag | Bagged mix only. The 10 in the field is an example price, and a warning shows while it is unchanged. |
| Labor | Optional. A rate per square foot, charged on the slab area. |
| Other materials | Optional flat amount for rebar, forms or base. |
Worked example: a 10 × 12 ft slab, 4 in thick
Arithmetic checkedThese are the calculator's own example values: ready-mix, a 10% allowance and round illustrative prices chosen for easy arithmetic. They are not quotes and not market prices.
| Step | Math | Result |
|---|---|---|
| Volume of the pour | 10 × 12 × (4 ÷ 12) | 40 ft³ |
| Volume with allowance | 40 × (1 + 10 ÷ 100) ÷ 27 | 1.6296 yd³ |
| Concrete material, at an example $100 per yd³ | 1.6296 × 100 | $162.96 |
| Delivery and fees, at an example $50 delivery and $75 short-load | 50 + 75 + 0, because 1.63 yd³ is below the 4 yd³ minimum | $125.00 |
| Labor, at an example $2.00 per ft² | 120 × 2 | $240.00 |
| Other materials, an example flat amount | 100 | $100.00 |
| Total estimated cost | 162.96 + 125 + 240 + 100 | $627.96 |
| Cost per square foot | 627.96 ÷ 120 | $5.23 |
| Cost per cubic yard (all-in) | 627.96 ÷ 1.6296 | $385.34 |
| You would see | $627.96 total estimated cost | |
Disclaimer
Results are planning estimates based on the dimensions and assumptions you enter. They are not engineering, structural or building-code advice. Product yields, densities and coverage vary by manufacturer, batch and site conditions. Check product labels, your supplier and your local building department before you order materials or start work. Read the full calculation disclaimer.
Accuracy
What affects your estimate
The formula is simple. What moves the answer is whether your prices are real quotes, which fees apply and how the supplier bills the volume.
Ready-mix is volume times price
The cost uses the exact volume with allowance, 1.6296 yd³ for the example, and does not round to a quarter yard. If your supplier bills in steps or has a minimum, choose I know the volume, enter the volume you will be billed and set the allowance to 0%.
Bags change the material line
The same 44 ft³ pour takes 74 bags of 80 lb mix, 98 of 60 lb or 118 of 50 lb, and the material line is the bag count times your price per bag. Delivery, minimum order and short-load fees belong to ready-mix, so they are ignored when you choose bags.
The short-load fee depends on the minimum you enter
With a 4 yd³ minimum the 1.63 yd³ example is below it, so the short-load fee is added. With a 1.5 yd³ minimum it is not, because 1.63 is above it. A volume exactly equal to the minimum is not below it. Suppliers set their own minimums and fees, so ask yours.
The allowance moves the price
With no allowance the slab is 40 ft³, or 1.4815 yd³. With 10% it is 1.6296 yd³. At an example price of $100 per yd³ the concrete line is $148.15 against $162.96, so a few percent of allowance is a real amount of money.
Labor and per-area rows are for slabs
Labor is a rate times the slab area, so a 10 × 12 ft slab at an example $2.00 per ft² is 120 × 2 = $240. A round column or a volume you type has no area, so it has no labor line and no cost per square foot. The cost per cubic yard (all-in) row appears for every shape.
Small pours and columns
A 12 in column 4 ft high is π × 0.5² × 4 = 3.1416 ft³. With a 10% allowance that is 3.4558 ft³, or 0.128 yd³, which is 3.4558 ÷ 0.60 = 5.76, so 6 bags of 80 lb. Ask suppliers about minimum orders before you price a very small pour as ready-mix.
This calculator quotes no prices, and prices vary by region, supplier, date and order size, so ask for a written quote. It does not design concrete work: slab thickness, reinforcement, base and subgrade must meet your local code and your designer or inspector. See the calculation disclaimer.
Common mistakes
Leaving the example price in the field
The 100 per cubic yard and the 10 per bag are round illustrations so the calculator shows a result on first load. They are not what concrete costs where you live. The calculator warns while they are unchanged, so type your own quote.
Pricing only the concrete
Delivery, pump, washout, forms, rebar, base and labor are separate lines on most jobs. Use the fees, Labor and Other materials fields, or the total will be low.
Comparing quotes on different volumes
One supplier may quote 2 yd³ and another 1.75. The Cost per cubic yard (all-in) row divides the total by the same volume, so you can compare quotes fairly.
Entering thickness in feet
The thickness field takes a plain number as inches. Typing 0.33 for a 4 in slab gives a fraction of the concrete you need.
Skipping the allowance
Spillage, uneven ground and bowed forms all take extra concrete, and running short mid-pour is worse than ordering a little more. Keep some allowance, and know that 10% is a convention rather than a rule.
Questions people ask
How much does a concrete slab cost?
This calculator does not publish prices, because they vary by region, supplier, date and order size. Enter the ready-mix or bag price from your own written quote and add delivery, labor and other materials, and it totals the job. Without a quote, any price you type is only an illustration.
How do I calculate the cost of concrete?
Find the volume in cubic yards, add an allowance, and multiply by the price per cubic yard. For a slab, volume = length × width × thickness in inches ÷ 12 cubic feet, divided by 27. If you only need the volume or the bags, use the Concrete Calculator.
How many cubic yards of concrete for a 10 × 12 ft slab, 4 inches thick?
It is 40 ft³, or 1.4815 yd³. With a 10% allowance it is 44 ft³, or 1.6296 yd³. That is the volume the calculator prices.
Should I use ready-mix or bags?
The calculator does not decide for you, because it depends on the two prices and fees you enter. For the example pour, bagged mix takes 74 bags of 80 lb, 98 of 60 lb or 118 of 50 lb, using the yields on one product's data sheet. The guide on how many bags of concrete you need explains the counts.
What is a short-load fee?
It is a charge some suppliers add when an order is below their minimum volume. Enter the minimum order and the fee from your quote and the calculator adds the fee only when the volume with allowance is below the minimum. If you enter a fee but no minimum, it is not applied and the calculator says so.
Does it include rebar, forms, base or a pump?
Not by itself. Put a pump in Other fees for ready-mix, and rebar, forms or base in Other materials as a flat amount. It does not size reinforcement or a base: those come from your local code and your designer or inspector.
How much does a yard of concrete weigh?
Plain concrete is about 4,050 lb per cubic yard at 150 lb per cubic foot, which matters for trucks and forms. The guide on how much a yard of concrete weighs gives weights by yards, slab thickness and bag size.
Related calculators and guides
Sources
Where the numbers come from
- QUIKRETE Concrete Mix #1101 data sheet yield per bag for 80, 60 and 50 lb bags, accessed October 17, 2026.
- NIST Handbook 44 (2026), Appendix C exact conversions, including 27 cubic feet per cubic yard, accessed October 17, 2026.