Concrete Bags per Cubic Yard (40 vs 60 vs 80 lb, and Ready-Mix)
How many 40, 60, and 80 lb bags of concrete it takes to make a cubic yard, what each bag yields, and the point where ready-mix delivery becomes the cheaper, saner choice.
It takes about 45 × 80 lb bags, 60 × 60 lb bags, or 90 × 40 lb bags to make one cubic yard of concrete, because a cubic yard is 27 cubic feet and those bags yield roughly 0.60, 0.45, and 0.30 cubic feet each. Bagged mix is fine for small pours, but once a job passes about one cubic yard the bag count and mixing labor make ready-mix delivery the cheaper, faster option.
“How many bags of concrete are in a yard?” is one of the most-searched concrete questions, and the answer decides whether you buy a pallet of bags or call a ready-mix supplier. It comes down to two facts: how much mixed concrete each bag makes, and how many cubic feet are in a cubic yard. Get those straight and you can price any pour in your head.
This guide gives you the per-bag yields, the bags-per-yard numbers for every common size, and the honest crossover point where delivery wins. To size a specific pour, start with How Much Concrete Do I Need? and then use the concrete calculator — it reports both a bag count and a ready-mix figure side by side.
What one bag actually yields
A bag of concrete mix is sold by its dry weight, but what you care about is the wet, mixed volume it produces. The standard yields are:
| Bag size | Yield per bag | Bags per cubic foot |
|---|---|---|
| 40 lb | 0.30 cu ft | ~3.3 |
| 60 lb | 0.45 cu ft | ~2.2 |
| 80 lb | 0.60 cu ft | ~1.7 |
These are the same constants the concrete calculator uses, so a hand estimate and the tool will agree.
Bags per cubic yard
A cubic yard is 3 ft × 3 ft × 3 ft = 27 cubic feet. Divide 27 by each bag’s yield and you get the bags needed to build a full yard:
Bags per cubic yard = 27 ÷ (yield per bag)
| Bag size | Yield | Bags per cubic yard |
|---|---|---|
| 40 lb | 0.30 cu ft | 90 bags |
| 60 lb | 0.45 cu ft | 60 bags |
| 80 lb | 0.60 cu ft | 45 bags |
Those are theoretical counts with no waste. In the real world you add about 10%, so a cubic yard is closer to 50 × 80 lb bags. Either way, the takeaway is stark: a single cubic yard is a mountain of bags.
A worked example
Suppose you’re pouring a small landing that comes to 0.87 cubic yards — a 8 × 8 ft slab at 4 inches, with waste. That’s 0.87 × 27 = 23.5 cubic feet. Priced in bags:
- 80 lb:
23.5 ÷ 0.60 ≈ 40 bags - 60 lb:
23.5 ÷ 0.45 ≈ 53 bags - 40 lb:
23.5 ÷ 0.30 ≈ 79 bags
Forty 80 lb bags is doable for a determined DIYer with a mixer, but you can already see how the numbers punish the smaller sizes. Bump the same slab to a full 10 × 10 ft and you’re at 62 bags — the point where most people call for delivery.
Where ready-mix takes over
The crossover is about one cubic yard. Here’s the logic:
- Below ~1 yard: Bags win. There’s no delivery minimum, no truck to schedule, and you mix only what you need. Great for post holes, small pads, steps, and repairs.
- Above ~1 yard: Ready-mix wins. At 45–50 bags per yard, mixing becomes an all-day job, the material cost per yard rises, and the risk of an uneven, cold-jointed pour climbs with every batch you mix by hand.
Many suppliers offer a short-load or “trailer-mix” option for pours between roughly 1 and 4 yards, bridging the gap when you’re past bag territory but below a full truck. It costs more per yard than a full load but far less than the equivalent pile of bags plus your weekend.
The concrete calculator makes this call for you: enter your dimensions and it leads with a bag count for small pours and switches to a rounded-up ready-mix figure once you cross a cubic yard.
Don’t forget waste — and thickness
Every number above is before the 10% waste margin that spillage and over-dug forms demand, and all of it hinges on getting your slab thickness right in the first place. An extra inch of depth quietly adds a quarter more concrete — and a quarter more bags. For the common depth and volume traps that blow up bag counts, read Concrete Slab Thickness & Estimating Mistakes, and see How Much Concrete Do I Need? for the full volume method.