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Know exactly how much concrete to order, in yards, before you call the supplier.

This concrete yard calculator turns the length, width and depth of your slab, driveway, patio, footing, wall or column into cubic yards, cubic feet, cubic meters, bag counts and a cost estimate — instantly, and for free.

Start calculating →

Concrete Yard Calculator

Enter length, width and depth using the unit dropdown next to each field.

0Cubic Feet
0Cubic Yards
0Cubic Meters

Estimated bags needed

Bag sizeBags
40 lb bags0
50 lb bags0
60 lb bags0
80 lb bags0

Estimated cost

Enter a price per yard
Free Forever No sign-up, no paywall, no hidden fees — ever.
Instant Results Yardage, bags and cost calculated the moment you click.
Mobile Friendly Built to work smoothly on the jobsite from any phone.
Accurate Estimates Standard industry formulas for yards, feet, meters and bags.

How to Use the Calculator

1 Enter dimensions

Type the length, width and depth (or diameter and height for a column).

2 Select units

Choose feet, inches, yards or meters independently for each field.

3 Add waste allowance

Pick 5–15% extra to cover spillage and uneven subgrade.

4 Enter price (optional)

Add your supplier's price per cubic yard to see an estimated cost.

5 Click Calculate

Get instant cubic yards, cubic feet, cubic meters and bag counts.

What Is a Concrete Yard Calculator?

A concrete yard calculator is a small piece of math wearing a friendly interface. Instead of asking you to remember that a cubic yard holds 27 cubic feet, or that an 80 lb bag covers roughly 0.6 cubic feet, it takes your project's length, width and depth and does the conversion for you. Type in the size of a slab, driveway, patio, sidewalk, footing, wall or column, and the calculator returns cubic feet, cubic yards, cubic meters, a bag count across four common bag sizes, and an estimated cost if you supply a price per yard.

The reason "yards" specifically matter is that ready-mix concrete is sold by the cubic yard almost everywhere in North America. Suppliers quote a price per yard, delivery trucks are rated by how many yards they carry, and minimum order sizes are usually expressed in yards. Homeowners comparing a bagged-concrete approach against a ready-mix delivery need the same unit to compare fairly, which is exactly what this concrete yardage calculator is built to provide.

How to Calculate Concrete

Every concrete volume calculation starts from the same three measurements: length, width and depth (sometimes called thickness). Multiply the three together and you get volume. The only real trick is keeping the units consistent, which is why this tool lets you pick feet, inches, yards or meters independently for each field and converts everything internally before doing the math.

Volume = Length × Width × Depth
Cubic Yards = Cubic Feet ÷ 27
Example: a patio measuring 12 ft long, 10 ft wide and 4 in (0.333 ft) thick has a volume of 12 × 10 × 0.333 = 40 cubic feet. Divide by 27 and that's about 1.48 cubic yards — call it 1.5 to 1.6 cubic yards once a 10% waste allowance is added.

Understanding Cubic Yards

A cubic yard is a cube measuring one yard, or three feet, on every side. Because volume scales in three dimensions, that single cube contains 3 × 3 × 3, or 27, cubic feet. This is the conversion factor behind every concrete slab calculator, and it's worth memorizing if you order concrete more than once: cubic feet divided by 27 gives cubic yards, and cubic yards multiplied by 27 gives cubic feet back again.

Cubic meters show up mostly outside North America, where ready-mix is sold metrically. One cubic yard is about 0.7646 cubic meters, so a project that comes out to 10 cubic yards is roughly 7.65 cubic meters. This calculator converts to cubic meters automatically so the same tool works whether your supplier quotes yards or meters.

Estimating Concrete Bags

Not every pour is big enough to justify a ready-mix truck. Small footings, fence post holes, repairs and short sidewalk sections are often filled with bagged concrete mix instead. The math is the same volume calculation, just measured against how much finished concrete a single bag yields once water is added.

40 lb bag
Yields about 0.30 cubic feet, so roughly 90 bags fill one cubic yard.
50 lb bag
Yields about 0.375 cubic feet, so roughly 72 bags fill one cubic yard.
60 lb bag
Yields about 0.45 cubic feet, so roughly 60 bags fill one cubic yard.
80 lb bag
Yields about 0.60 cubic feet, so roughly 45 bags fill one cubic yard.

For anything larger than about 1 cubic yard, most contractors find ready-mix delivery cheaper and far less physically demanding than mixing dozens of bags by hand.

Concrete Cost Estimation

Ready-mix concrete is typically priced per cubic yard, with the rate depending on the region, the mix's compressive strength, any additives, and how far the truck has to travel. A common national range is somewhere between 125 and 180 dollars per cubic yard for standard mixes, though short-load fees, weekend surcharges and pump truck rental can add to the final invoice. Enter your supplier's quoted price per yard into the calculator's cost field and it will multiply that rate by the cubic yardage, including any waste allowance you've selected, so the number you see is close to what you'll actually be billed before taxes and delivery fees.

Bagged concrete is priced per bag rather than per yard, and while a single bag looks inexpensive, the per-yard cost of bagged mix is usually higher than ready-mix once you account for how many bags a full yard requires. This calculator's cost estimate is meant for ready-mix; when using bags, multiply the bag count by your local per-bag price to get a comparable total.

Tips Before Ordering Concrete

Measure twice. Small errors in length or width get multiplied by depth, so a rounding mistake on one side of a driveway can throw off the whole order.
Always add a waste allowance. Uneven subgrade, formwork gaps and spillage mean the poured volume is almost never exactly the calculated volume.
Confirm your supplier's minimum order. Many ready-mix companies charge a short-load fee below a certain number of yards, which can make bagged concrete more economical for tiny pours.
Check slab thickness codes locally. Driveways, sidewalks and structural slabs often have minimum thickness requirements set by local building codes.

Common Mistakes

Mixing units without converting, such as entering length in feet and depth in inches without adjusting the math.
Forgetting the waste allowance entirely and ordering the exact calculated volume, then running short mid-pour.
Assuming bagged concrete is always cheaper than ready-mix, when in fact bags cost more per cubic yard past a certain project size.
Ignoring local frost depth or code-required thickness when setting the depth field, leading to a slab that doesn't meet code.

Frequently Asked Questions

What is a concrete yard calculator?

A concrete yard calculator is a tool that converts the length, width and depth of a slab, driveway, patio or other structure into the volume of concrete needed, expressed in cubic yards, along with related figures like cubic feet, cubic meters, bag counts and estimated cost.

How do I calculate concrete volume?

Multiply length by width by depth, all measured in the same unit, to get cubic feet or cubic meters. Divide cubic feet by 27 to convert to cubic yards, since one cubic yard contains 27 cubic feet.

How many cubic feet are in one cubic yard?

One cubic yard equals 27 cubic feet, because a yard is 3 feet on each side and 3 × 3 × 3 equals 27.

How many 80 lb bags make one cubic yard?

It takes roughly 45 bags of 80 lb pre-mixed concrete to make one cubic yard, since each 80 lb bag yields about 0.6 cubic feet and 27 cubic feet divide into about 45 bags.

How much does one yard of concrete cost?

Ready-mix concrete typically costs between 125 and 180 dollars per cubic yard depending on region, mix strength and delivery distance, though prices can run higher in areas with high demand or limited suppliers.

How much extra concrete should I order?

Most contractors add a waste allowance of 5 to 10 percent to cover spillage, uneven subgrade and measurement variance, and up to 15 percent for irregular shapes or ground that has not been finely graded.

How thick should a concrete slab be?

A standard residential slab is typically 4 inches thick, driveways for passenger vehicles are usually 4 to 6 inches, and slabs supporting heavier loads such as trucks or equipment are often poured 6 to 8 inches thick.

From the Blog

In-depth articles on pouring, curing and estimating concrete are in the works. Check back soon.

Slab vs. Footing: Which Depth Do You Need? A closer look at thickness requirements for common residential pours. Coming Soon
Ready-Mix vs. Bagged Concrete When it makes financial sense to switch from bags to a delivery truck. Coming Soon
Curing Concrete in Cold Weather Practical tips for pours scheduled during colder months. Coming Soon