Concrete Bags vs Ready Mix: Which Should You Use?

Concrete bags vs ready mix comes down to one number: your volume. Under about half a cubic yard, use bags. Over about 1 cubic yard, which is 45 or more 80lb bags, order ready-mix. Between those two lines it is a judgment call based on how many helpers you have and how much time you can give the pour.

Run your dimensions through the Concrete Calculator first. Once you know your cubic yards, the decision usually makes itself. For the full sizing walkthrough, start with how much concrete do I need.

How many bags of concrete are in a cubic yard?

One cubic yard is 27 cubic feet. That works out to 45 x 80lb bags, 60 x 60lb bags, or 90 x 40lb bags. The yields behind those counts are simple: an 80lb bag makes 0.60 cubic feet, a 60lb bag makes 0.45, and a 40lb bag makes 0.30.

Those numbers are the whole argument. Forty-five bags is not a shopping trip. It is a pallet, a truck with real suspension, and a full day of lifting. If your math lands near or above 45 bags, you are already in ready-mix territory even if the bags look cheaper on the shelf.

If you want the yield table broken down bag by bag, see how many cubic feet in a bag of concrete.

How many yards does a concrete truck hold?

A standard ready-mix truck carries roughly 8 to 10 cubic yards at a full load. That is 360 to 450 80lb bags in one drum. Almost no residential job fills a truck. A 20x20 driveway at 4 inches thick is 4.94 cubic yards, only about half a load.

So the real question is not whether your job is big enough to fill a truck. It is whether your job is big enough to justify calling one. Suppliers will happily deliver 2 yards. They will just add a short-load fee for it.

What is a short-load fee?

Suppliers typically charge a short-load fee on small orders, commonly anything under about 1 cubic yard. The truck, the driver, and the drive time cost the same whether they bring you 1 yard or 9, so the fee covers the gap.

Fee amounts vary by region, by supplier, and by season, so do not trust a number you read online. Call two local plants, give them your yardage and your address, and ask for the delivered total including any short-load or minimum-order charge. That five-minute call settles the bags vs ready mix debate better than any article can.

Is it cheaper to mix your own concrete?

For small jobs, usually yes. For big jobs, the sticker price stops being the point. The real limit on bagged concrete is not money. It is time and labour.

Here is what people miss. Concrete starts setting from the moment it is wet. On a large pour you are racing yourself. If you mix bag 40 an hour and a half after bag 1, the early concrete has already stiffened, and you get a cold joint: a weak seam where fresh mix never properly bonded to the older mix. That seam is where slabs crack.

A 10x10 slab at 4 inches is 1.23 cubic yards, or 56 x 80lb bags. Picture that honestly. Fifty-six bags is hours of mixing, hauling, and screeding, and every minute of it is on the clock against the set time. Two people with one mixer will struggle. One person with a wheelbarrow will not finish before the first section goes hard.

Which projects need bags and which need a truck?

Use this as a quick sort. All slab figures assume 4 inches thick.

• Fence posts (a few holes): bags, easily. Use fast-setting mix, pour it dry into the hole, add water on top. No mixing, no wheelbarrow.
• Small pad, under about 1/2 cubic yard: bags. Roughly 22 or fewer 80lb bags. One person with a wheelbarrow can handle it in a morning.
• 10x10 slab, 1.23 cubic yards, 56 x 80lb bags: ready-mix. This is past the 1-yard line. Bags are possible with a crew and a rented mixer, but the cold joint risk is real.
• 12x12 slab, 1.78 cubic yards, 80 x 80lb bags: ready-mix. Eighty bags is not a DIY mixing job.
• 20x20 driveway, 4.94 cubic yards, 223 x 80lb bags: ready-mix, no debate. Still only about half a truckload.

Not sure which row you are in? Measure, then check the Concrete Calculator.

Wheelbarrow or rented mixer?

A wheelbarrow and a hoe work fine up to maybe 10 or 15 bags. Past that your arms give out and your mix gets sloppy, because tired people add extra water to make mixing easier. Extra water means weaker concrete.

A rented mixer changes the math. It roughly doubles what a small crew can place per hour and it keeps each batch more consistent. If you are committed to bags for something in the 20 to 45 bag range, rent the mixer. Do not try to muscle it.

Either way, set up a mixing station close to the forms. Hauling wet concrete 60 feet across a yard eats more time than the mixing does.

Does ready-mix give better quality?

It gives better consistency, which is most of what quality means here. Ready-mix arrives pre-mixed and uniform. Every yard in the drum has the same water content, the same aggregate, the same strength.

Bags are only as consistent as the person mixing them. Batch 3 gets a little more water. Batch 30 gets mixed 30 seconds shorter because your shoulders hurt. Each variation is minor. Across 56 bags they add up to a slab with uneven strength and uneven surface finish.

The other advantage is the continuous pour. One truck, one placement, no seams. That matters most for anything structural or anything that has to look good.

What do you need ready before the truck arrives?

Everything. Trucks charge waiting time, and the driver is not there to help you build forms.

Before you book the delivery, have your forms built, staked, and squared. Have the base compacted and your reinforcement placed. Have your screed board, floats, edger, and gloves laid out. Have your helpers on site and briefed. Have a plan for where the chute reaches and how you will move concrete that lands short.

Confirm the exact yardage the day before. Ordering a bit long is cheaper than being a quarter yard short with half a slab already curing. That is the one place where bags and ready-mix mix well: keep a few bags on hand as insurance.

Fast-setting mix for posts

Fence and mailbox posts are their own category. Fast-setting mix goes in dry. You drop the post, plumb it, pour the dry mix around it, then add water per the bag instructions. It stiffens in minutes.

Do not use fast-setting mix for a slab. You will not get across the surface before it goes off. It is a post product, not a pour product.

Bottom line

Under about half a cubic yard, bags are simpler and cheaper, and you skip the delivery fee entirely. Over about 1 cubic yard, which is 45 or more 80lb bags, order ready-mix and get one continuous, consistent pour. In between, decide based on your crew size and whether you can rent a mixer.

Remember the anchors: 1 cubic yard equals 27 cubic feet equals 45 x 80lb bags, and a truck holds roughly 8 to 10 yards. Get your number from the Concrete Calculator, then call two local suppliers for a delivered quote. The math tells you which side of the line you are on, and the quote tells you what it costs.