Quikrete Concrete Calculator

Calculate your concrete volume in cubic yards, bags, and cubic feet instantly and free.

  • Free
  • No sign-up
  • Instant results

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How to use it

  1. Enter length in feet
  2. Enter width in feet
  3. Enter thickness in inches
  4. Read cubic yards, bags, and cubic feet results

Quikrete Concrete Calculator lets you turn the dimensions of any slab, walkway, or footing into the exact amount of concrete you need. You enter length and width in feet and thickness in inches; the tool converts to cubic feet, then to cubic yards (27 ft³ = 1 yd³) and finally to 80‑lb bags using the proven 0.6 ft³ per bag rate. Knowing cubic yards helps you get accurate quotes from suppliers, while bag count tells you how many 80‑lb sacks to order. The results appear instantly, so you can compare options, adjust dimensions, and avoid costly over‑ordering. Use the numbers to plan delivery, budget, and ensure your project stays on schedule. The calculator also shows the total cubic feet, which is useful for estimating material for forms and reinforcement. Because the bag yield is fixed, you can round up to the nearest whole bag to guarantee enough mix.

Pro tips

  • Add 5‑10% extra for waste and spillage.
  • Round up bag count to the next whole bag.
  • Order bags in multiples of 5 to reduce shipping costs.
  • Double‑check thickness conversion from inches to feet.

Real-life examples

  • Homeowner pouring a 12 ft × 12 ft patio 4 in thick.
  • Contractor estimating concrete for a 30 ft driveway 6 in thick.
  • DIYer calculating material for an 8 ft × 10 ft shed floor 3 in thick.

Case study

Mike needed a 10 ft × 10 ft slab 4 in thick. Using the calculator he saw he required 1.24 yd³, which translates to 56 bags. He ordered 56 bags, avoided a $200 over‑order, and completed the slab on schedule.

Frequently asked questions

How many 80‑lb bags do I need for a 5 ft × 8 ft slab 3 in thick?
Enter 5, 8, 3 – the calculator will give you cubic feet, divide by 0.6 to get bags (round up).
What is the difference between cubic feet and cubic yards?
1 cubic yard equals 27 cubic feet; the tool shows both so you can communicate with suppliers.
Can I use the calculator for foundations deeper than 12 in?
Yes, just enter the thickness in inches; the calculator handles any depth.
Why should I round up the bag count?
Bags come in whole units and the 0.6 ft³ per bag is an average; rounding up ensures you have enough mix.
Do I need to include a waste factor?
Add 5‑10 % extra to the bag total for spillage and uneven subgrade.