How to use it
- Enter length in feet
- Enter width in feet
- Enter thickness in inches
- View cubic yards, bags, and cubic feet results
The 1‑4‑8 Concrete Mix Calculator turns the three dimensions you input—length, width and thickness—into the exact volume of concrete required. It first converts thickness from inches to feet, multiplies the three measurements to get cubic feet, then divides by 27 to show cubic yards and by 0.6 to estimate how many 80‑lb bags you’ll need. Knowing the cubic yards helps you compare quotes from suppliers, while the bag count tells you how many packages to order. The results appear instantly, so you can adjust dimensions on the fly and see how the material needs change. Use the numbers to budget, schedule deliveries, and avoid costly over‑or under‑ordering. The calculator also displays the total cubic feet, which is useful for ordering mixed‑in‑place trucks that charge by the foot. Because the bag estimate uses the standard 0.6 ft³ per 80‑lb bag, you can trust the count when ordering from retail stores. Adjust thickness to see immediate changes in yardage and bag count.
Pro tips
- Add a 5‑10% waste allowance to the bag total
- Round up the bag count; you can’t purchase a fraction of a bag
- Order one extra bag for spillage or an uneven sub‑base
- Double‑check the thickness conversion; a 2‑inch error can double material
Real-life examples
- Homeowner pouring a 12‑ft × 10‑ft patio 4‑in thick
- Contractor estimating concrete for a 20‑ft × 30‑ft slab 6‑in deep
- Landscaper planning a 50‑ft long walkway 3‑in thick
Case study
Mike needed a 15 × 20 ft driveway 5 in thick. Using the calculator he saw he required 1.85 cubic yards, which translated to 108 bags. He ordered 110 bags, avoided a second delivery, and finished on budget.