Concrete Calculator
Calculate exactly how much concrete you need — in bags or cubic yards — plus cost and mix recommendations.
Always order extra. Running short mid-pour is a disaster.
Your Concrete Estimate
Bags Needed
Cost Estimate
⭐ Concrete Pour Essentials
Three items that separate a flat, durable concrete pour from a cracked, dusty mess. Even pros use the same gear — it's not complicated, you just need the right pieces.
High-Strength Concrete Mix (5000 PSI)
For driveways, footings, and anywhere that takes weight, 5000 PSI mix is worth the small price bump over standard 4000 PSI. It cures harder, resists freeze-thaw cracking better, and is the same mix most KC-metro contractors use for driveways.
View on Amazon →Penetrating Concrete Sealer
New concrete looks great for one season, then weather, salt, and oil ruin it. A penetrating siloxane sealer applied once a year keeps the surface from spalling and dramatically extends the concrete's life. Apply on a dry day, two thin coats.
View on Amazon →Magnesium Float & Trowel Set
The magnesium float is what gives concrete that smooth, professional finish — not the cheap wooden ones from a big-box store. A 16-inch magnesium float plus a steel trowel handles patios, driveways, and slabs up to a few hundred square feet without trouble.
View on Amazon →As an Amazon affiliate, HomeCalc Tools earns a small commission if you purchase through these links — at no extra cost to you. We only recommend products we would actually use ourselves.
How Much Concrete Do I Need?
The amount of concrete you need depends on the project dimensions. Concrete is measured in cubic yards for ready-mix delivery or bags for smaller projects. A standard 80-lb bag of Quikrete makes 0.6 cubic feet of concrete. One cubic yard equals 27 cubic feet, so you'd need about 45 bags of 80-lb concrete per cubic yard.
Bags vs. Ready-Mix: Which Should You Use?
For projects under 1 cubic yard (roughly a 10x10 slab at 4 inches), bagged concrete is practical. Above 1 yard, ready-mix delivery is almost always better — it's cheaper per yard, saves hours of mixing, and gives you a consistent pour. Most concrete companies have a 1-yard minimum with delivery fees of $50-$150. For anything over 2 yards, ready-mix is a no-brainer.
Concrete Cost in 2026
Ready-mix concrete costs $130-$175 per cubic yard delivered, depending on mix type and your location. An 80-lb bag of Quikrete costs $5-$7 at Home Depot or Lowe's, working out to about $225-$315 per cubic yard — significantly more expensive but convenient for small jobs. For a typical 10x20 patio slab (4" thick), expect to spend $300-$500 on concrete alone, plus $200-$400 for gravel base, forms, and rebar.
Tips for a Successful Concrete Pour
Always order 10% more concrete than your calculation shows — forms are never perfect, and running short mid-pour creates a weak cold joint. Prep your base with 4-6 inches of compacted gravel for drainage. Use rebar or wire mesh for any slab — it adds $50-$100 but prevents cracking. Pour on a mild day (50-80°F) and keep the concrete moist for at least 3 days while it cures. Rushing the cure is the #1 cause of weak, cracking concrete.
Mistakes That Crack Concrete Within Two Years
Almost every cracked concrete slab we see traces back to one of four mistakes: pouring on frozen or saturated ground, skipping the rebar or wire mesh on slabs thicker than two inches, not adding control joints every 8-10 feet, or finishing the surface while it's still bleeding water. Each of those mistakes is free to avoid if you plan ahead — and each one costs $1,500-$5,000 to fix later. Concrete is unforgiving once it sets, so the time to get it right is in the half-hour after the truck pours.
When to Hire It Out vs. DIY
A flat 4x6 ft pad for a grill or AC condenser is a confident DIY project. A driveway, sidewalk run, or anything thicker than 4 inches is almost always cheaper and better hired out — the mixing, finishing, and timing are harder than they look, and the cost of failure (a cracked, sloped driveway that holds water) is many times the cost of paying a pro. If you're somewhere in between, rent a mixer rather than wheelbarrowing dry mix — consistent water-to-cement ratio is the single biggest factor in long-term durability.