Show the math
- Convert to feet (inches ÷ 12, centimeters ÷ 30.48): Length 10 ft; Width 10 ft; Thickness 4 in = 0.3333 ft
- Volume = 10 × 10 × 0.3333 × 1 = 33.3333 ft³
- Net volume = 33.3333 ft³ ÷ 27 = 1.2346 yd³ (× 0.0283168 = 0.9439 m³)
- Order quantity = 1.2346 yd³ × (1 + 10%) = 1.358 yd³ = 36.6667 ft³
- 80 lb bags = 36.6667 ft³ ÷ 0.6 ft³ per bag = 61.11 → 62 bags (always round up)
- Weight = 36.6667 ft³ × 150 lb/ft³ = 5,500 lb
How to measure
If you know the size of the area, enter length, width and thickness. If you already have a volume from another calculator, enter it in the volume box in cubic yards, cubic feet or cubic meters and it replaces the dimensions.
The bag yield is the volume of wet concrete that one bag makes. It is printed in the manufacturer’s data. Standard 80 lb mix yields about 0.60 ft³, 60 lb about 0.45 ft³, 50 lb about 0.375 ft³ and 40 lb about 0.30 ft³.
How many bags are in a cubic yard?
A cubic yard is 27 ft³, and the bag count is simply 27 divided by the yield of the bag. That gives the numbers below. Always round up to a whole bag, and add waste.
| Bag size | Yield | Bags per yd³ | Bags per ft³ of concrete |
|---|---|---|---|
| 80 lb | 0.6 ft³ | 45 | 1.67 |
| 60 lb | 0.45 ft³ | 60 | 2.22 |
| 50 lb | 0.375 ft³ | 72 | 2.67 |
| 40 lb | 0.3 ft³ | 90 | 3.33 |
Worked example: a 10 × 10 ft slab at 4 in
- Convert to feet (inches ÷ 12, centimeters ÷ 30.48): Length 10 ft; Width 10 ft; Thickness 4 in = 0.3333 ft
- Volume = 10 × 10 × 0.3333 × 1 = 33.3333 ft³
- Net volume = 33.3333 ft³ ÷ 27 = 1.2346 yd³ (× 0.0283168 = 0.9439 m³)
- Order quantity = 1.2346 yd³ × (1 + 10%) = 1.358 yd³ = 36.6667 ft³
- 80 lb bags = 36.6667 ft³ ÷ 0.6 ft³ per bag = 61.11 → 62 bags (always round up)
- Weight = 36.6667 ft³ × 150 lb/ft³ = 5,500 lb
| Quantity | Result |
|---|---|
| Net volume | 1.235 yd³ (33.33 ft³, 0.944 m³) |
| Order with 10% waste | 1.36 yd³ (1.04 m³) |
| 80 lb bags | 62 |
| 60 lb bags | 82 |
| Weight at 150 lb/ft³ | 5,500 lb |
The same slab takes 62 bags of 80 lb mix, 82 of 60 lb, 98 of 50 lb or 123 of 40 lb. Smaller bags are easier to carry but there are more of them, and the total weight of dry mix is the same, about 2.5 tons.
What one bag covers
It helps to know the area a single bag covers, for patching or small pads. The coverage is the yield divided by the thickness in feet.
| Thickness | Area | Metric |
|---|---|---|
| 1 in | 7.20 ft² | 0.67 m² |
| 2 in | 3.60 ft² | 0.33 m² |
| 3 in | 2.40 ft² | 0.22 m² |
| 4 in | 1.80 ft² | 0.17 m² |
| 6 in | 1.20 ft² | 0.11 m² |
Bags per pallet and delivery
Retailers sell bagged concrete on pallets. An 80 lb pallet usually holds 42 bags and a 60 lb pallet 56 bags, though counts vary by product. The pallet calculator turns bags into pallets and shows the weight, which matters for delivery. A pallet of 80 lb bags weighs well over a ton.
Check the bag for the actual yield. Special products, such as high-strength mixes, rapid-setting mixes or lightweight concretes, yield differently from standard mix. Edit the yields under Advanced assumptions and the whole page recalculates.
Mixing tips for bagged concrete
- Use the water amount on the bag. Too much water weakens the concrete. See how to mix bagged concrete.
- Mix in small batches that you can place within the working time.
- Use a mixer for more than a few bags. Hand mixing a slab’s worth is tiring and gives uneven results.
- Keep bags dry and off the ground. Old, lumpy bags make weak concrete.
Bags or ready-mix?
The break-even depends on prices. Below about a yard, bags are easier. Above about two yards ready-mix is usually better. Use the cost calculator with your quotes, and the bagged vs ready-mix guide for the full comparison.
Frequently asked questions
How many 80 lb bags of concrete make one cubic yard?
About 45. Divide 27 ft³ by the 0.60 ft³ yield of an 80 lb bag.
How many 60 lb bags make a yard?
60 bags at 0.45 ft³ each.
How many 50 lb bags make a yard?
72 bags at 0.375 ft³ each.
How many 40 lb bags make a yard?
90 bags at 0.30 ft³ each.
How much does a pallet of concrete weigh?
A pallet of 42 bags of 80 lb mix holds about 3,360 lb of dry mix, plus the pallet.
Do all brands have the same yield?
No. The figures here match standard mix data. Check the bag, and edit the yield if yours is different.
How many bags for a 4 × 4 ft slab at 4 in?
About 10 bags of 80 lb mix, with 10% waste.
Sources
Estimate only. Results depend on the numbers you enter, ground conditions and your supplier. For structural work consult a licensed engineer and follow local codes. Brand names such as Quikrete and Sakrete are used only to cite published product data. This site is not affiliated with any brand.