Let's talk numbers. Based on real data from the National Ready Mixed Concrete Association, a standard 4-inch-thick slab is the most common for residential patios and walkways. But if you're pouring a driveway, you'll want 5 or 6 inches. Our calculator handles any thickness from 3 to 6 inches (or 7.6 to 15.2 cm). Here's what you're looking at for a typical 10x10 foot slab at 4 inches thick: - Volume: about 1.23 cubic yards - 80-lb bags needed: roughly 55 (if you're mixing by hand) - Cost for ready-mix: around $130 to $150 per cubic yard delivered - Cost for bagged concrete: about $6 per bag, so $330 total - Labor to place it: $50 to $100 per cubic yard if you hire help But honestly, these numbers shift depending on your region and the time of year. That's why the calculator pulls from multiple sources and lets you adjust the waste factor. Don't trust a single number — trust the tool. In my experience, the biggest mistake people make is forgetting the waste factor. Even a perfect pour loses 5% to 10% to spillage, uneven ground, or just mismeasuring. Our calculator defaults to 10% waste, but you can slide it up or down. Use 5% if you're a pro with a laser level. Use 15% if you're a first-timer on uneven ground.

Not sure whether to order a truck or haul bags from the home center? Here's a quick comparison based on typical costs and volumes. | Factor | Ready-Mix Concrete | Bagged Concrete (80-lb bags) | |--------|-------------------|------------------------------| | Cost per cubic yard | $110–$150 (typical $130) | $5–$7.50 per bag (about $300–$450 per yard) | | Yield per bag | N/A | 0.55–0.65 cubic feet (typical 0.6) | | Best for | Large slabs (over 2 yards), driveways, foundations | Small projects, tight access, DIY patios under 2 yards | | Labor needed | Minimal — truck dumps it | Heavy — mixing and hauling bags | | Waste factor | Lower (5–10%) | Higher (10–15%) | | Delivery fee | Often included or $50–$100 extra | Free if you haul yourself | For a 10x10 slab at 4 inches thick (about 1.23 cubic yards), ready-mix will cost you around $160 to $185 delivered. Bagged concrete will run you about $330 in bags alone, plus your sweat equity. If you've got access for a truck, ready-mix is usually cheaper and way less work. But if your site is tight or you're only pouring a small pad, bags make sense. One caveat: ready-mix trucks typically have a minimum order of 2 to 3 yards. So if your project is under that, you might pay a short-load fee. Our calculator accounts for that by letting you input your total volume and compare both options.

Once you've got your numbers from the calculator, here's what to do next: 1. **Add 10% to 15% for waste** — even if you're careful. I've found that 10% is the sweet spot for most flatwork. 2. **Order ready-mix at least 2 days in advance** — especially in summer when demand spikes. 3. **If using bags, buy them all at once** — same batch number ensures consistent color. 4. **Check your local building codes** — some areas require a minimum of 3,000 psi for driveways. 5. **Have a plan for leftover concrete** — you can't return extra ready-mix, but you can make stepping stones or a small pad. This tool won't do the heavy lifting for you, but it'll save you from over-ordering or running short mid-pour. And that's a win.