How Many Bags of Concrete Are in a Yard?

How Many Bags of Concrete Are in a Yard?

It takes 45 80 lb bags, 60 60 lb bags, or 90 40 lb bags of pre-mix concrete to make one full cubic yard. Those numbers assume no waste, so on a real job you should count on a few extra bags per yard. Bag-mix concrete is dense stuff, and a yard is more material than most people expect.

I mix a lot of small pours by hand, and the question that trips people up every time is how many bags it actually takes to fill a yard. A cubic yard is 27 cubic feet, and once you know how many cubic feet each bag yields, the rest is simple division. The problem is that the bag doesn’t yield anywhere near as much volume as the dry weight suggests, because you’re adding water and the powder settles tight.

Bags to make a yard of concrete

Here’s the breakdown by bag size. Each bag of dry mix yields a set amount of finished concrete once it’s mixed with water, and dividing 27 cubic feet by that yield gives you the bags per yard.

Bag size	Yield per bag (cu ft)	Bags per cubic yard
40 lb	0.30	90
50 lb	0.375	72
60 lb	0.45	60
80 lb	0.60	45
90 lb	0.675	40

So when someone asks about 80 lb bags per yard of concrete, the answer is 45. For 60 lb bags in a cubic yard, it’s 60. It’s an easy pattern to remember: heavier bags, fewer of them.

Why bag concrete gets expensive fast

Forty-five 80 lb bags is 3,600 lb of material to haul, open, and dump one at a time. That’s a full day of mixing for one person, and the bagged price per yard usually runs two to three times what ready-mix costs delivered. My rule of thumb: once a pour crosses about one cubic yard, I call the ready-mix plant instead of buying bags. Below a yard, bags win because most plants charge a short-load fee under a full truck.

If you want to check the crossover point for your own job, run the numbers in the concrete bag calculator and compare against a ready-mix quote.

Working out bags for your slab

You don’t order concrete by the yard when you’re buying bags at the store, you buy a bag count. So the real workflow is: figure your volume, then convert to bags. Start by finding your cubic yards with the concrete yardage calculator, then multiply.

For example, a small landing that works out to 0.5 cubic yards:

• 0.5 yards × 45 (for 80 lb bags) = 23 bags
• Add 5 to 10 percent waste, so order 25 bags

That waste margin matters. Bags tear, some mix stays stuck in the wheelbarrow, and the subgrade is never perfectly level. Running two bags short with the truck idling is a bad afternoon. For a deeper look at how yield is measured, read our note on cubic feet per bag.

The formula behind the counts

If you’d rather work it out yourself, the math is one division:

bags per yard = 27 cubic feet ÷ bag yield in cubic feet

Every count in the table above comes straight from that. An 80 lb bag yields about 0.6 cubic feet, so 27 ÷ 0.6 = 45. The yields printed on the bag are the manufacturer’s numbers, and they’re consistent across the major brands, so you can trust them within a bag or two.

Mixing tips that save bags

• Add water slowly. Over-wet mix is weaker and it slumps, which actually costs you yield because it spreads thin.
• Keep the finished thickness honest. An extra half inch across a 10 by 10 pad eats several extra bags.
• Dump and screed in sections so mix doesn’t set up before you strike it off.
• Buy a couple more bags than the count says and return the unopened ones.

If you’re still at the planning stage and not sure how much total concrete the project needs, our guide on how much concrete do I need walks through measuring the whole job before you ever touch a bag.

FAQ

How many 80 lb bags of concrete make a yard?

Forty-five 80 lb bags make one cubic yard. Each bag yields about 0.6 cubic feet, and 27 divided by 0.6 is 45. Buy a few extra to cover waste and torn bags.

How many 60 lb bags are in a cubic yard?

Sixty 60 lb bags fill a cubic yard, since each yields roughly 0.45 cubic feet. That’s a lot of mixing by hand, so most crews switch to ready-mix at that volume.

Is it cheaper to buy bags or ready-mix for a yard?

For a full yard, ready-mix delivered is almost always cheaper than 45 bags, even with a short-load fee. Bags only win on small pours under about a cubic yard.

How many bags of concrete do I need for a 10x10 slab at 4 inches?

A 10 by 10 slab at 4 inches is about 1.23 cubic yards, which is roughly 56 80 lb bags before waste. At that size, price out a ready-mix load first.

Does the bag count change for 40 lb bags?

Yes. It takes 90 40 lb bags to make a yard because each one yields only about 0.3 cubic feet. Smaller bags mean far more of them and a lot more lifting.

How much waste should I add to my bag count?

Add 5 to 10 percent. Uneven subgrade, spillage, and mix left in the mixer all eat into your usable volume, and coming up short mid-pour is worse than a couple of returned bags.

Need an exact bag count for your job? Plug your dimensions into the concrete bag calculator and get 40, 60, and 80 lb totals in seconds.