How Many Bags of Concrete Are in a Cubic Yard?
One cubic yard is 27 cubic feet of concrete. Divide that by the yield printed on the bag and you get the count. Here is the short answer for the most common bag size.
The exact count is 45 × 80 lb bags: 27 ft³ ÷ 0.60 ft³ per bag. The 50-bag figure adds the standard 10% allowance for spillage, uneven ground, and forms that are not perfectly level. Running short mid-pour leaves a weak cold joint, so the cushion is worth it.
Bags per cubic yard, by bag size (with 10% waste)
Bag Table: 1, 2 and 3 Cubic Yards, by Bag Size
Exact counts are the mathematical minimum, rounded up. The "with waste" counts multiply the volume by 1.10 before dividing, which is the number to actually buy. Counts are figured from the total volume, so the 3 yd³ row is not just the 1 yd³ row times three. Yields: 80 lb bag = 0.60 ft³, 60 lb = 0.45 ft³, 50 lb = 0.375 ft³, 40 lb = 0.30 ft³.
| Volume | 80 lb exact | 80 lb +10% | 60 lb exact | 60 lb +10% | 50 lb exact | 50 lb +10% | 40 lb exact | 40 lb +10% |
|---|---|---|---|---|---|---|---|---|
| 1 yd³ (27 ft³) | 45 | 50 | 60 | 66 | 72 | 80 | 90 | 99 |
| 2 yd³ (54 ft³) | 90 | 99 | 120 | 132 | 144 | 159 | 180 | 198 |
| 3 yd³ (81 ft³) | 135 | 149 | 180 | 198 | 216 | 238 | 270 | 297 |
Going the other way: one 80 lb bag covers 0.60 ft³, so a single bag stretches to about 0.022 yd³. That is why small repairs are measured in bags and real pours are measured in yards — the bag count gets unwieldy fast.
How the Math Works
There is no special formula here, just a unit conversion and a division.
- Cubic yards to cubic feet: multiply by 27. (1 yd³ = 27 ft³.)
- Add waste: multiply cubic feet by 1.10 for a 10% cushion.
- Bags: divide by the yield printed on the bag and round up.
Bags = (yd³ × 27) ÷ yield per bag, rounded up
Worked example for 80 lb bags: 1 × 27 = 27 ft³, and 27 ÷ 0.60 = 45 exactly, so 45 bags. With waste: 27 × 1.10 = 29.7 ft³, and 29.7 ÷ 0.60 = 49.5, so 50 bags to buy.
The same math in 60 lb bags: 27 ÷ 0.45 = 60 bags exact, or 66 with the cushion. In 40 lb bags: 27 ÷ 0.30 = 90 bags exact, or 99 with the cushion. The concrete is identical; only the bag size, and the number of trips to the store, changes.
One Cubic Yard Is the Crossover: Bags or Truck?
A cubic yard is exactly where this decision gets interesting, because ready-mix suppliers bill a 1 yd³ minimum. Below a yard, you pay for a full yard you do not use, plus a delivery fee, and often a short-load surcharge on top — that padding is what makes bags cheaper on small pours. At a full yard and beyond, you are using what you paid for, and the truck's per-yard price takes over.
At the example prices used on the main calculator ($6.50 per 80 lb bag, $160 per cubic yard, $75 delivery), one cubic yard looks like this:
| 1 yd³ of concrete | Cost | What you handle |
|---|---|---|
| Bags, exact (45 × 80 lb) | $292.50 | 3,600 lb of bags to mix |
| Bags, with waste (50 × 80 lb) | $325.00 | 4,000 lb of bags to mix |
| Ready-mix truck (1 yd³ + delivery) | $235.00 | Place and finish only |
| Ready-mix with waste (1.1 yd³ + delivery) | $251.00 | Place and finish only |
At these prices the crossover lands at roughly three quarters of a cubic yard: below that, the truck's minimum charge and delivery fee outweigh the bag premium; above it, the truck wins on price and wins on labor everywhere. Fifty 80 lb bags is two full tons of lifting, mixing, and wheelbarrowing, and a yard of concrete placed from bags takes hours longer than the same yard off a chute. Bags still make sense at a yard or more when the truck cannot reach the pour, when you are working in stages over several days, or when local ready-mix quotes come in far above the example prices. Run your own quotes through the cost comparison on the calculator before deciding.
Know Your Slab Size Instead?
Most pours start from dimensions, not yards. The free calculator works from your length, width, and thickness, then figures cubic yards, cubic feet, and bag counts live, and compares bag cost against a ready-mix quote with your local prices. Working from a specific slab? See the 10×10 slab bag guide, the 12×12 slab bag guide, or the 10×20 slab bag guide.
Cubic Yard Bag FAQ
How many 80 lb bags of concrete are in a cubic yard?
45 bags exactly (27 ft³ ÷ 0.60 ft³ per bag). Buy 50 bags to cover the standard 10% waste allowance for spillage and uneven forms.
How many 60 lb bags of concrete are in a cubic yard?
60 bags exactly (27 ft³ ÷ 0.45 ft³ per bag), or 66 bags with the 10% waste cushion. In 40 lb bags the count is 90 exact, 99 to buy.
How many bags of concrete do I need for 2 cubic yards?
In 80 lb bags: 90 exact, 99 to buy with waste. In 60 lb bags: 120 exact, 132 to buy. At 2 yd³ a ready-mix truck is almost always cheaper and far less work than mixing 100-plus bags by hand.
Is it cheaper to buy bags or order a truck for 1 cubic yard?
Usually the truck, at typical prices. One yard runs about $293–$325 in 80 lb bags versus $235–$251 delivered ready-mix, and the truck saves you mixing two tons of concrete. Bags pull ahead below roughly ¾ yd³, where the truck's 1 yd³ minimum and delivery fee dominate. Check with your own quotes in the cost comparison.
Estimates Only
Results are planning estimates. Actual concrete needs vary with ground conditions, form accuracy, over-excavation, and product yield. Bag yields follow manufacturer figures for standard mixes; your product may differ slightly. Always order a little extra — running short mid-pour creates a weak cold joint. For structural work (foundations, load-bearing footings, retaining walls), consult a licensed professional and follow your local building code.