12×12 Patio = 80 Bags Of 80-Lb
The Breakeven Point: Where Bags Stop Making Sense
A 12×12-foot patio at 4 inches thick requires 80 bags of 80-lb concrete. At $4–$5 per bag, that's $320–$400 in material costs alone. But scale up to 12×16 feet (107 bags = $428–$535) or 16×20 feet (222 bags = $888–$1,110), and ready-mix concrete becomes dramatically cheaper—often by $200–$600.
Ready-mix trucks typically cost $150–$200 for delivery plus $8–$12 per cubic yard. A 16×20-foot patio at 5 inches thick needs 4.9 cubic yards. Total cost: roughly $190 (delivery) + $49–$59 (material) = $240–$250. Compare that to 222 bags at $4.50 each, and you're saving nearly $750.
The Math: Bags Work for Small Projects
For patios under 10×10 feet (55 bags), bagged concrete still wins financially. You'll spend $220–$275 and avoid delivery fees. The labor tradeoff matters here—mixing 55 bags takes 3–4 hours with two people. It's manageable but exhausting.
At 12×12 feet (80 bags), you're at the inflection point. Labor stretches to 5–6 hours. If you value your time at $25/hour, labor costs balloon to $125–$150, closing the gap with ready-mix. At 12×16 feet and beyond, ready-mix saves both money and your back.
Hidden Costs That Tip the Scale
Bagged concrete often hides expenses:
- Mixing equipment rental: A concrete mixer costs $40–$60/day. Budget this if you don't own one.
- Wheelbarrow labor: Each bag goes into a mixer, then wheelbarrow to the slab. That's 107 trips for a 12×16 patio.
- Waste factor: Most DIYers overbuy by 15–20% to avoid running short mid-pour. That's 10–15 extra bags at $45–$75.
- Cleanup: Dried concrete spills and residue require scrubbing. Ready-mix leaves minimal waste.
Ready-mix trucks also arrive with integrated pumps (for $100–$150 extra), eliminating wheelbarrow work entirely on large projects.
Your Decision Framework
Choose bags if:
- Your patio is smaller than 10×10 feet
- You have access to a mixer
- You're pouring alone and accept slower progress
- You enjoy the hands-on process
Choose ready-mix if:
- Your project exceeds 12×12 feet
- You need the job finished in one day (essential for proper finishing)
- Your site has truck access within 100 feet of the slab
- You want consistent concrete quality (ready-mix is factory-controlled)
For a 12×12 patio, bags are borderline—the savings are real but modest ($75–$150 in your favor). For 16×20 feet and larger, ready-mix isn't just cheaper; it's the only practical choice. Use our concrete calculator to find your exact cubic yardage, then call three ready-mix suppliers for quotes before committing to 200+ bags.
