Concrete Patio Calculator
Enter the length, width, and thickness of your patio to calculate the concrete volume in cubic feet and cubic yards. You can also estimate the number of concrete bags and the approximate material cost.
Concrete Patio Calculator
Estimate the concrete your patio needs in cubic yards, cubic feet, bags, weight, and approximate material cost.
⚙️ More calculation options
Planning a new patio is exciting, but figuring out how much concrete to order can be surprisingly difficult. A small mistake in your measurements can leave you with too little concrete on pouring day—or extra material that you paid for but cannot use.
Whether you are building a small backyard seating area or a large outdoor entertaining space, this calculator gives you a practical starting point for planning your concrete order.
How Much Concrete Do I Need for a Patio?
The amount of concrete required depends on three measurements: the length, width, and thickness of your patio.
A patio that is 12 feet long and 16 feet wide has an area of 192 square feet. If the concrete is 4 inches thick, the exact volume is approximately 2.37 cubic yards.
Adding a 10% allowance brings the estimated order quantity to approximately 2.61 cubic yards.
This extra allowance helps account for minor measurement errors, uneven ground, and concrete lost during mixing or pouring. It is a planning allowance, not a substitute for accurate measurements or proper site preparation.
How to Calculate Patio Concrete
You do not need complicated mathematics to estimate the concrete for a rectangular patio.
First, calculate the surface area:
Patio area = Length × Width
Next, convert the concrete thickness from inches to feet:
Thickness in feet = Thickness in inches ÷ 12
Then calculate the concrete volume:
Concrete volume in cubic feet = Area × Thickness in feet
Finally, convert cubic feet to cubic yards:
Cubic yards = Cubic feet ÷ 27
For example, a patio measuring 10 feet by 12 feet with a thickness of 4 inches requires:
- Area: 120 square feet
- Thickness: 0.333 feet
- Exact volume: 40 cubic feet
- Exact concrete quantity: 1.48 cubic yards
With a 10% allowance, you would plan for approximately 1.63 cubic yards.
Patio Concrete Thickness: What Should You Use?
The thickness of a concrete patio depends on the intended use, ground conditions, reinforcement, and local construction requirements.
A 4-inch slab is a common starting point for residential patio planning, but it is not automatically appropriate for every project. A patio supporting heavy loads or connecting to a driveway may require a different design.
Before ordering concrete, make sure the thickness you enter matches your project requirements. Increasing the thickness from 4 inches to 6 inches increases the concrete volume by 50% for the same patio area.
For example, a 200-square-foot patio requires approximately:
| Thickness | Exact concrete |
|---|---|
| 4 inches | 2.47 cubic yards |
| 5 inches | 3.09 cubic yards |
| 6 inches | 3.70 cubic yards |
These quantities are before adding a waste allowance.
How Many Bags of Concrete Do I Need for a Patio?
For smaller patios, you may choose bagged concrete instead of ordering ready-mix.
The number of bags depends on the yield of the specific product. An 80-pound bag commonly yields approximately 0.60 cubic feet, although you should always check the manufacturer’s packaging.
For example, if your patio requires 40 cubic feet of concrete:
40 ÷ 0.60 = approximately 67 bags
With a 10% allowance, the quantity increases to approximately 74 bags.
For larger patios, ready-mix concrete may be more practical because mixing dozens or hundreds of bags requires substantial time and labor.
Ready-Mix Concrete or Bagged Concrete?
The best option depends on the size of your patio and how easily concrete can be delivered to the site.
Bagged concrete may work well for small patios, repairs, and locations where a concrete truck cannot reach.
Ready-mix concrete is generally more convenient for larger patios because the concrete arrives mixed and can be placed more quickly.
When comparing prices, remember that ready-mix delivery fees, minimum order quantities, and labor are separate from the concrete price itself.
What Does a Concrete Patio Cost?
The concrete material is only one part of the total patio cost.
Your project may also require:
- Excavation and removal of existing material
- Gravel or compacted subbase
- Wooden or metal forms
- Reinforcement
- Concrete delivery
- Labor
- Finishing and control joints
- Sealing or other surface treatments
The calculator can estimate the concrete material cost if you enter a price per cubic yard. It does not calculate the complete cost of constructing a patio.