Use bagged concrete when your project is under 1 cubic yard (about 45 bags of 80-lb mix). Use ready-mix concrete for anything larger. The crossover is where the ready-mix truck’s short-load fee is offset by not mixing dozens of 80-lb bags by hand. For a 10×10 slab at 4 inches, that means ready-mix wins on total cost and effort.
Side-by-Side Comparison
| Factor | Bagged Concrete (DIY) | Ready-Mix Truck |
|---|---|---|
| Best project size | Under 1 yd³ | 1–10+ yd³ |
| Material cost | $7–$8 per 80-lb bag (~$315–$360/yd³) | $150–$200/yd³ |
| Minimum order | 1 bag | 3 yd³ (+ short-load fee if less) |
| Short-load fee | None | $60–$150 for under minimum |
| Labor | You mix every bag | You place and finish; truck delivers |
| Timing pressure | Low (mix as you go) | High (90-min window) |
| Crew needed | 1–2 | 2–4 |
| Practical max | ~0.5–1.0 yd³/day (by hand) | Any size |
| Strength | 4,000 psi at 28 days (standard bags) | 3,000–5,000 psi (specify when ordering) |
Where the Numbers Break
For an 80-lb bag at $7.50:
- 1 bag = 0.60 cu ft
- 1 cubic yard = 27 cu ft → $337.50 per yd³ in bags
Ready-mix at $175/yd³:
- The bag-vs-truck material difference is about $163 per cubic yard
For a 2-cubic-yard pour: bags cost $675 in material, ready-mix costs $350–$400 (depending on short-load fee). Ready-mix wins clearly. Add 1–2 hours of labor saved in mixing at $25/hr per person and the advantage grows further.
Worked example — 1.5 cubic yard patio (roughly 12×12 ft at 4 in):
| Bagged | Ready-Mix | |
|---|---|---|
| Material | $506 (67 bags x $7.50) | $175 (1.5 yd³ x ~$175/yd³) |
| Short-load fee | — | $100 (under 3-yd min) |
| Total materials | $506 | $275 |
| Mixing labor | 5–6 hrs (by hand) | 0 hrs |
| Advantage | Ready-mix saves $231 + hours of work |
The break-even is around 1 cubic yard when you factor in the short-load fee.
When Bags Win
Projects under 0.5 cubic yards: Posts, small footings, repair patches. The short-load fee alone (up to $150) can cost more than the material savings from bulk pricing.
Remote or tight-access locations: If a ready-mix truck cannot reach your site — narrow gates, steep slopes, or no street access — bags are the practical option. Some areas also lack concrete plants nearby, making delivery expensive.
Weekend-pace projects: Bags let you work at your own pace. Ready-mix requires a crew on standby the moment the truck arrives.
Small repairs: Quikrete Vinyl Concrete Patcher and similar specialty repair products have no ready-mix equivalent.
A Third Option: Volumetric Concrete Mixers
Between bags and traditional ready-mix sits a less-known option: the volumetric mixer, sometimes called a mobile or metered mixer. These specialized trucks mix concrete on-site from bulk raw materials and dispense exactly the volume you need — no short-load fee and no minimum order. You pay per cubic yard of actual concrete used.
Volumetric mixer pricing typically runs $175–$250 per cubic yard (slightly above standard ready-mix) but eliminates the short-load penalty. This makes them economical for pours in the 0.5–2 cubic yard range where a standard truck would charge full short-load fees. Availability varies by region — search for “volumetric concrete” or “metered concrete” in your area.
Ordering Ready-Mix: What to Specify
When you call a concrete plant, they will ask:
- Volume in cubic yards (use the concrete calculator to get this)
- PSI — specify 3,000 for patios, 4,000 for driveways, 5,000 for structural
- Slump — the wetness of the mix; 4–5 inch slump is standard for flatwork; 3-inch slump for walls; 6-inch slump only if a pump is being used
- Fiber — polypropylene fiber ($10–$20 extra/yd³) reduces surface cracking and eliminates the need to place wire mesh
- Air entrainment — essential in freeze-thaw climates; ask for 5–7% air for exterior flatwork
- Delivery time — give a 30-minute buffer from when your crew and tools will be ready
Also ask about the plant’s short-load fee policy. Some waive it for local deliveries or regulars; others enforce it strictly. Get the fee amount before committing.
Physical Limits of Bagged Concrete
Mixing 80-lb bags is demanding physical work. An average person can mix about 10–12 bags per hour using a rented electric drum mixer, or 15–20 bags per hour with a larger contractor-grade mixer. Hand-mixing in a wheelbarrow works for 1–5 bags; after that, quality and consistency suffer.
Mixing 62 bags for a 10×10 slab takes 3–4 hours for one person with a rented mixer — in addition to the time needed to screed and finish. Ready-mix turns that into a 1–2 hour pour with proper crew.
Renting a Mixer for Bagged Projects
If you need to mix more than 10–15 bags, a rented electric drum mixer ($50–$75/day) is worthwhile. A drill-powered paddle mixer works for post-hole mixes but is too slow for slab volumes. For post-setting specifically, Quikrete Fast-Setting Concrete poured dry into the hole needs no mixing at all — see concrete-for-fence-posts.
Common Mistakes with Ready-Mix
Adding water at the truck. Adding water at the job site reduces strength. Quikrete and the Portland Cement Association both note that each additional inch of slump from added water reduces compressive strength by approximately 250 psi. If the mix arrives too stiff, ask the driver about water reducer (mid-range admixture) instead.
Not having enough crew. A three-person crew is the minimum for a slab over 100 sq ft: one managing the chute, one spreading concrete with a shovel, and one screeding. Without enough hands, sections begin to stiffen before they are screeded.
Forgetting to oil the forms. Wet concrete bonds to bare wood. Coat the inner face of form boards with vegetable oil or commercial form release before the pour. Oiled forms strip in minutes; bare wood forms often need prying and damage the slab edge.
Safety note: Both bags and ready-mix concrete are highly alkaline (pH 12–13) and cause skin burns with prolonged contact. Wear nitrile gloves, long sleeves, and safety glasses. Rinse any skin contact immediately with water.
For cost breakdown by project type, see concrete-slab-cost.