Quick Answer: Bags Per Cubic Yard
Here's the number most people are looking for. This table covers the three standard bag sizes you'll find at Home Depot, Lowe's, or any hardware store.
| Bag Size | Yield per Bag | Bags per Cubic Yard |
|---|---|---|
| 40 lb bag | 0.30 cu ft | 90 bags |
| 60 lb bag | 0.45 cu ft | 60 bags |
| 80 lb bag | 0.60 cu ft | 45 bags |
You need 45 bags of 80 lb concrete to make one cubic yard. That's the most common size people buy for DIY projects.
These numbers come from the manufacturer's stated yield, which is printed on every bag. One cubic yard = 27 cubic feet. Divide 27 by the bag's yield, and you get the count.
The Math Behind It
The formula is straightforward:
For an 80 lb bag of concrete mix that yields 0.60 cubic feet:
27 ÷ 0.60 = 45 bags
For a 60 lb bag yielding 0.45 cubic feet:
27 ÷ 0.45 = 60 bags
For a 40 lb bag yielding 0.30 cubic feet:
27 ÷ 0.30 = 90 bags
Keep in mind — these are theoretical yields. In practice, you'll lose some concrete to mixing, spillage, and overfill. Add 10% to your bag count to be safe.
Quikrete vs Sakrete: Same Bags, Same Counts?
Pretty much, yes. Both Quikrete and Sakrete list nearly identical yields for their standard concrete mixes:
| Brand | 80 lb Yield | 60 lb Yield | Bags per Yard (80 lb) |
|---|---|---|---|
| Quikrete | 0.60 cu ft | 0.45 cu ft | 45 |
| Sakrete | 0.60 cu ft | 0.45 cu ft | 45 |
| Quikrete 5000 | 0.60 cu ft | 0.45 cu ft | 45 |
The yield is the same across the major brands for their standard mix. Where they differ is strength — Quikrete 5000 reaches 5,000 PSI vs. the standard 4,000 PSI. The bag count stays the same either way.
Check the yield number printed on the back of the bag, not just the weight. Some specialty mixes (like fast-setting or high-strength) have slightly different yields.
Cost Comparison: Bags vs. Ready-Mix Truck
This is where things get interesting. Bagged concrete is convenient for small jobs, but the cost per yard adds up fast.
| Method | Cost per Yard (Approx.) | Best For |
|---|---|---|
| 80 lb bags ($5-7 each) | $225 – $315 | Under 1 cubic yard |
| 60 lb bags ($4-5 each) | $240 – $300 | Under 0.5 cubic yards |
| Ready-mix delivery | $125 – $175 | 1+ cubic yards |
The crossover point is roughly 1 cubic yard. Below that, bags make sense because you avoid delivery fees and truck minimums. Above that, ready-mix is cheaper, faster, and you won't spend hours mixing by hand.
Most ready-mix companies have a minimum order of 1 yard, and some charge a "short-load fee" (usually $30-$75) if you order less than their full-truck minimum (typically 7-10 yards).
Mixing 45 bags of 80 lb concrete by hand is exhausting. That's 3,600 pounds of material to open, pour, mix, and place. If your project needs more than about 30 bags, seriously consider ordering a ready-mix truck instead.
When NOT to Use Bags
Bags are great for small, contained projects. They're not great for everything.
Use bags when:
- You need less than 1 cubic yard
- You're setting fence posts or mailbox posts
- You're patching or repairing small sections
- You don't have access for a concrete truck
- You need to pour in stages over several days
Order ready-mix when:
- Your project needs more than 1 cubic yard
- You're pouring a slab, patio, or driveway
- You need consistent strength and finish quality
- You want to pour the entire project at once (fewer cold joints)
- Time matters — a truck pours in minutes, not hours
Not sure how many yards your project needs? Start with the concrete yard calculator to get an exact cubic yard estimate, then decide between bags or truck.
Bags Needed by Common Project Size
Here's a quick reference for common small projects, assuming 80 lb bags and 4-inch slab thickness:
| Project | Size | Cubic Yards | 80 lb Bags |
|---|---|---|---|
| Fence post hole | 10″ × 30″ deep | 0.04 yd³ | 2 bags |
| Mailbox post | 12″ × 24″ deep | 0.03 yd³ | 2 bags |
| Small pad | 4 × 4 ft × 4″ | 0.20 yd³ | 9 bags |
| Sidewalk section | 3 × 10 ft × 4″ | 0.37 yd³ | 17 bags |
| Small patio | 8 × 10 ft × 4″ | 0.99 yd³ | 45 bags |
| Single car pad | 10 × 20 ft × 4″ | 2.47 yd³ | 111 bags* |
*At 111 bags, you should absolutely order ready-mix. That's over 8,800 pounds of material to mix by hand.
Calculate Your Exact Bag Count
Enter your slab dimensions and we'll give you cubic yards, bag count, and cost estimate.
Open Concrete Calculator →Tips for Mixing Bagged Concrete
If you've decided bags are the way to go, here are a few things that'll save you time and frustration:
- Use a mixer if you have access to one. You can rent a portable concrete mixer for $50-75/day. It beats mixing in a wheelbarrow by a mile.
- Add water slowly. Start with about 3 quarts per 80 lb bag and add more as needed. Too much water weakens the concrete.
- Mix no more than you can place in 15 minutes. Concrete starts setting faster than you think, especially in hot weather.
- Buy 10% more bags than you calculate. Some material always gets lost during mixing, and your forms might not be perfectly level.
- Work in the early morning or evening in summer. Concrete in 95°F heat sets too fast to work with properly.
Related Guides
Working on a concrete project? These guides cover the other calculations you'll need:
- How to Calculate Concrete Yardage — Slabs, driveways, footings, and cylinder formulas
- How Much Does a Yard of Concrete Cover? — Coverage by slab thickness
- How Many Cubic Yards Do I Need? — Master guide for all materials
- Cubic Yard Calculator — General-purpose volume calculator
- Concrete Cost Per Yard Calculator — Estimate your total material cost