Concrete Patio Calculator
Plan your patio pour with the right amount of concrete. Enter the length and width of the patio and get cubic yards, bag counts and an estimated cost straight away.
Patios are poured 4 inches thick in almost every case, so this calculator starts there. If a hot tub, outdoor kitchen or heavy structure will sit on the patio, raise the thickness to 5 or 6 inches in the tool and add reinforcement under that section.
Concrete Patio Calculator
Concrete for a patio slab, with bag counts and an estimated cost.
Most patios are poured 4 inches thick on a compacted gravel base.
Cost estimate uses the ready mix price of $165 per cubic yard and $5.50 per 80 lb bag set for this calculator. Estimates only, confirm quantities with your supplier before ordering.
Quick answers for common patio sizes
Figures are for a 4 inch thick patio and include 10 percent extra for waste.
| Patio size | Cubic yards | 80 lb bags | 60 lb bags |
|---|---|---|---|
| 8 x 8 ft | 0.87 | 40 | 53 |
| 10 x 10 ft | 1.36 | 62 | 82 |
| 12 x 12 ft | 1.96 | 88 | 118 |
| 12 x 16 ft | 2.61 | 118 | 157 |
| 16 x 16 ft | 3.48 | 157 | 209 |
Worked example
A 12 x 16 ft patio at 4 inches: 12 x 16 x 0.333 = 64 cubic feet, which is 2.37 cubic yards. With 10 percent waste, plan on 2.61 cubic yards, or 118 bags of 80 lb mix if you are mixing it yourself.
Bags or a ready mix truck
A small patio under 1 yard, like an 8 x 8 ft at 0.87 yards with waste, is a realistic weekend bag job with a rented mixer. A 12 x 16 ft patio at 2.61 yards means 118 bags and a long day, so most people order a truck and finish the pour in under an hour.
Frequently asked questions
How much concrete for a 12 x 12 patio?
At 4 inches thick, a 12 x 12 ft patio needs 1.78 cubic yards before waste and 1.96 cubic yards with 10 percent added. That is 88 bags of 80 lb mix.
How thick should a patio slab be?
Four inches over a compacted gravel base is the standard for patios and walkways. Use 5 to 6 inches only where a hot tub or another heavy load will sit.
Can I pour a patio in sections?
Yes. Large patios are often split by control joints into sections, and each section can be calculated separately with this tool by entering that section size.
Does the calculator include the gravel base?
No. It calculates concrete only. Plan a compacted gravel base of about 4 inches under the slab and order that material separately.
Related calculators
Estimates only. Quantities and prices are guides, not quotes. Confirm final amounts with your supplier before you order.