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United States

Cubic Yards of Concrete Calculator

Find out how many cubic yards of concrete to order from the plant. The order is rounded up to the quarter yard, and small orders show the short-load fee most plants charge.

What are you pouring?
Patio, driveway, shed base, path
Length Width Thickness

Tip: you can type feet and inches, like 10' 6".

Reinforcement for slabs (optional)
Gravel base under slabs (optional)

Gravel weight changes from quarry to quarry: ask your supplier for the compacted weight and we turn the volume into tons.

Use your own prices (optional)

You need

– cu yd

–

Poured, it weighs about – lb.

Premixed bags

Bag Bags To carry Est. cost

Mixing it yourself (1:2:3)

QUIKRETE Portland Cement data sheet: concrete mix 1 part cement, 2 parts All-Purpose Sand, 3 parts All-Purpose Gravel; 5 to 6 bags of 94 lb per yd³. A 94 lb bag is the customary 1 cu ft of cement.

Ready-mix truck

–

If a contractor pours it

How we price

Link to this calculation Download estimate (PDF)

Your materials at a glance

How to calculate concrete

  1. Get cubic feet. Length × width × thickness, all in feet.
  2. Divide by 27. A cubic yard is 3 × 3 × 3 = 27 cubic feet.
  3. Add 5–10% extra. Running short with a truck on site is expensive.
  4. Round up to the plant's increment. Many plants sell in quarter yards; ask yours.

Worked example: a 24 × 24 ft garage floor, 5 inches thick

  1. Volume: 24 × 24 × (5 ÷ 12) = 240.0 cu ft = 8.89 cubic yards.
  2. Plus 5%: 9.33 cubic yards.
  3. Rounded up to the quarter yard, order 9.50 cubic yards: about one truck.

Cubic yards by area and thickness

Area 4 in 5 in 6 in
100 sq ft 1.23 1.54 1.85
200 sq ft 2.47 3.09 3.70
300 sq ft 3.70 4.63 5.56
400 sq ft 4.94 6.17 7.41
500 sq ft 6.17 7.72 9.26
750 sq ft 9.26 11.57 13.89
1,000 sq ft 12.35 15.43 18.52

No waste included: add 5–10% before ordering.

Concrete formulas by shape

All measurements in feet; divide inches by 12 first. Results are in cubic feet.

Slab
length × width × thickness
Round slab
π × (diameter ÷ 2)² × thickness
Continuous footing
total length × width × depth
Pad footing
length × width × depth × number of footings
Monolithic slab
length × width × thickness + perimeter band × (edge depth − thickness), where perimeter band = length × width − (length − 2 × edge width) × (width − 2 × edge width)
Bell footing
π × r² × pier height + π × bell height ÷ 3 × (R² + R × r + r²), with r = pier radius and R = bell radius
Wall
length × height × thickness
Column / pier
π × (diameter ÷ 2)² × height
Post hole
(hole area − post area) × depth; round hole π × (diameter ÷ 2)², square hole width²
Tube / ring
π × [(outer ÷ 2)² − (inner ÷ 2)²] × height
Curb & gutter
[curb depth × (curb height + flag thickness) + gutter width × flag thickness] × length
Steps (solid, n steps)
width × rise × run × (1 + 2 + … + n). With a landing, the landing is the top step: width × rise × [run × (1 + … + (n − 1)) + landing depth × n]

Cubic yards = cubic feet ÷ 27.

Frequently asked questions

How do I convert square feet to cubic yards of concrete?

Multiply square feet by the thickness in feet, then divide by 27. At 4 inches: square feet ÷ 81.

What is a short-load fee?

Plants often have a minimum load, commonly around 8–10 cubic yards. Below it they charge a fee for each missing yard, which can make a 1-yard order cost far more per yard than a full truck.

How much concrete fits in a truck?

Standard mixer trucks carry around 8–10 cubic yards; bigger jobs need more than one truck. Ask the plant for their exact size.

How much extra should I order?

5–10%. For ready-mix the plant cannot top you up easily, so err on the high side.

About the prices

Costs are estimated ranges with source and date, never a quote. Enter your local prices under "Use your own prices", or read how we estimate prices.