Concrete Square Feet to Yards Calculator
One cubic yard of concrete covers 81 square feet at 4 in thick, 54 sq ft at 6 in and 108 sq ft at 3 in.
Advanced options: waste, prices
NRMCA advises ordering 4 to 10 percent over the estimate.
Concrete needed (with 10% extra)
13.58 yd³
10.38 m³ · 333.33 ft³ before extra
Square feet: 1000 sq ft × 4 in. Over about 1 yd³: order ready-mix.
Premix bags
- 80 lb612
- 60 lb815
- 50 lb978
- 40 lb1223
- Ready-mix cost
- $2,173
- Weight
- 50,000 lb
Full breakdown
| Volume before extra | 12.35 yd³ · 9.44 m³ |
|---|---|
| With 10% extra | 13.58 yd³ |
| Weight (150 lb/ft³) | 50,000 lb · 25 tons |
| Pallets of 40 lb (80 bags each) | 16 |
| Pallets of 60 lb (56 bags each) | 15 |
| Pallets of 80 lb (42 bags each) | 15 |
| Truckloads at 12 yd³ | 2 |
| Truckloads at 8 yd³ | 2 |
Bag counts round up, as Quikrete's own calculator does. Cost uses your prices; delivery and short-load fees are extra.
Key takeaways
- Cubic yards = sq ft × thickness (ft) ÷ 27.
- 1 yd³ covers 81 sq ft at 4 in, 54 at 6 in.
- 2 yd³ cover 162 sq ft at 4 in.
- Add 10% for waste.
How Many Square Feet Does a Yard of Concrete Cover?
A cubic yard covers 324 ÷ thickness in inches square feet, because 27 ft³ × 12 = 324.
| Thickness | Sq ft per cubic yard |
|---|---|
| 3 in | 108 |
| 3.5 in | 92.6 |
| 4 in | 81 |
| 5 in | 64.8 |
| 6 in | 54 |
How to Convert Square Feet to Cubic Yards
yd³ = Square feet × (Thickness (in) ÷ 12) ÷ 27A 300 sq ft slab at 4 in: 300 × 0.333 ÷ 27 = 3.70 yd³, or 4.07 yd³ with 10% extra.
Concrete for 200 to 2,000 Square Feet
| Area | yd³ at 4 in | with 10% | yd³ at 6 in |
|---|---|---|---|
| 200 sq ft | 2.47 | 2.72 | 3.70 |
| 400 sq ft | 4.94 | 5.43 | 7.41 |
| 500 sq ft | 6.17 | 6.79 | 9.26 |
| 900 sq ft | 11.11 | 12.22 | 16.67 |
| 1,200 sq ft | 14.81 | 16.30 | 22.22 |
| 1,500 sq ft | 18.52 | 20.37 | 27.78 |
| 2,000 sq ft | 24.69 | 27.16 | 37.04 |
How Much Will 2 Yards of Concrete Cover at 4 Inches?
Two cubic yards cover 162 sq ft at 4 in thick, such as a 12×13.5 ft slab, before extra.
Worked Examples: Square Feet to Yards
300 sq ft patio at 4 in. 300 ÷ 81 = 3.70 yd³; with extra, 4.07 yd³.
1,000 sq ft garage floor at 4 in. 1,000 ÷ 81 = 12.35 yd³; with extra, 13.58 yd³, or 2 trucks at 12 yd³.
600 sq ft driveway at 5 in. 600 ÷ 64.8 = 9.26 yd³; with extra, 10.19 yd³.
Square Feet per Bag of Concrete
| Bag | Sq ft at 2 in | at 3 in | at 4 in |
|---|---|---|---|
| 80 lb | 3.60 | 2.40 | 1.80 |
| 60 lb | 2.70 | 1.80 | 1.35 |
| 40 lb | 1.80 | 1.20 | 0.90 |
Is a Yard of Concrete 3 by 3 by 3 Feet?
Yes, a cubic yard is 3 ft × 3 ft × 3 ft = 27 cubic feet; spread 4 in thick it covers 81 sq ft.
Concrete Needed for Common Floor Areas
Autocomplete shows people sizing whole floors by square footage; the table gives yards and trucks at 4 in with 10% extra.
| Area | Example | yd³ with 10% | Trucks (12 yd³) |
|---|---|---|---|
| 200 sq ft | 10×20 ft | 2.72 | 1 |
| 400 sq ft | 20×20 ft | 5.43 | 1 |
| 576 sq ft | 24×24 ft garage | 7.82 | 1 |
| 900 sq ft | 30×30 ft | 12.22 | 2 |
| 1,200 sq ft | 30×40 ft | 16.30 | 2 |
| 2,400 sq ft | 40×60 ft | 32.59 | 3 |
How to Measure Square Feet for Concrete
- Measure length and width in feet and multiply.
- For L-shapes, split into rectangles and add the areas.
- For circles, use 3.1416 × radius².
- For triangles, use ½ × base × height.
Square Feet to Bags of Concrete
For small areas, convert square feet straight to bags: at 4 in, one 80 lb bag covers 1.8 sq ft and one 60 lb bag 1.35 sq ft, so 20 sq ft takes about 12 bags of 80 lb with 10% extra.
Concrete Square Feet to Yards Calculator FAQ
How many yards of concrete do I need for a 12×12?
A 12×12 ft slab (144 sq ft) at 4 in needs 1.78 yd³, or 1.96 yd³ with extra.
How many yards of concrete for a 300 sq ft slab?
A 300 sq ft slab at 4 in needs 3.70 yd³, or 4.07 yd³ with extra.
How much concrete for 1,500 square feet?
1,500 sq ft at 4 in needs 18.52 yd³, or 20.37 yd³ with 10% extra (2 trucks).
Next step
Price the yards with the cost of concrete, or enter length and width in the concrete slab volume calculator.
Official sources
Last reviewed 2026-11-05. Numbers come from our tested engine; see how we calculate and our sources.