Concrete Calculator
Calculate the volume of concrete needed for slabs, footings, and columns. Results in cubic yards and cubic meters.
Project Type
ft
ft
in
%
Cubic Yards Needed
1.36
cubic yards (incl. 10% waste)
Volume Summary
- Cubic Feet
- 36.67 ft³
- Cubic Yards
- 1.36 yd³
- Cubic Meters
- 1.04 m³
Estimated Bags (hand mixing)
- 60 lb bags
- 82 bags
- 80 lb bags
- 62 bags
Estimates include 10% waste. For projects over ~1 cubic yard, ordering ready-mix concrete is usually more cost-effective than bagged mix. Always consult a contractor for structural applications.
Concrete Volume Formula
Slab: volume (ft³) = length (ft) × width (ft) × depth (ft). Convert to cubic yards: ÷ 27. Add 10% for waste. Example: 10 ft × 10 ft × 0.33 ft (4 in) = 33 ft³ ÷ 27 = 1.22 cubic yards + 10% = 1.35 cubic yards.
Frequently Asked Questions
- Cubic yards = (length × width × depth) ÷ 27 (all measurements in feet). Always add 10% waste factor for overages.
- Standard residential slabs are 4 inches thick. Driveways and areas with vehicle traffic typically require 6 inches.
- Approximately 45 bags of 80 lb concrete mix make 1 cubic yard. Use this to estimate bags if you are mixing by hand.