Concrete Calculator: How to Calculate for Any Project
From a small slab to a large footing — master the concrete calculation formula and avoid costly mistakes on your next pour.
Getting your concrete calculation right is one of the most critical steps in any hardscape project. Order too little and you'll get a cold joint — a visible, structurally weak seam. Order too much and you're paying for concrete to haul away.
Our Concrete Calculator handles the math automatically, including a waste factor.
How Thick Should Your Concrete Be?
- 4 inches: Residential sidewalks, patios, garage floors
- 5 inches: Driveways with passenger cars
- 6 inches: Driveways with heavy vehicles, boats, RVs
- 8–12 inches: Footings and load-bearing foundations
Bags vs. Ready-Mix Concrete
Overview of concrete calculator: how to calculate for any project
For projects under 1 cubic yard, mixing from bags is practical. One 80 lb bag yields 0.60 cubic feet, so a cubic yard requires about 45 bags. At $6–$8 per bag, a cubic yard from bags costs $270–$360.
Ready-mix concrete delivered costs $120–$180 per cubic yard. For anything over 1 yard, ready-mix wins on cost and quality.
Calculate Concrete Instantly
Get cubic yards, 60 and 80 lb bag counts, and cost range.
Important Tips for Your Pour
Project planning and measurement
- Order concrete for delivery on a weekday — weekend surcharges apply
- Have everything ready before the truck arrives — you have 60–90 minutes
- Keep concrete moist for 7 days after pouring (wet curing)
- Avoid working in temperatures below 40°F or above 90°F
- Add control joints every 8–10 feet to control cracking
For a complete overview of material calculators, see our Ultimate Guide to DIY Material Calculators.