Concrete Calculator
Estimate concrete for slabs, columns, walls, and solid steps. Get cubic yards, cubic meters, bag counts, and a material cost estimate from your dimensions.
Approximate QUIKRETE Concrete Mix 1101 yields. Each bag size is an alternative; check the yield on your product before ordering.
Material only. Delivery, labor, reinforcement and formwork are not included.
How to Calculate Concrete Volume and Bags
For a slab, enter length, width, and thickness. With imperial measurements: cubic yards = length (ft) × width (ft) × thickness (in) ÷ 324. A 10 ft × 10 ft slab at 4 inches thick needs about 1.23 cubic yards before waste. The optional 10% allowance increases this to about 1.36 cubic yards.
For a solid column, use the full diameter and height; for a wall, use length, height, and thickness. The staircase model adds up solid steps with equal rise and tread depth, without a separate landing. The results separate net volume from the optional 10% allowance. Choose the allowance appropriate to your project rather than treating 10% as a universal requirement.
Bag estimates use approximate QUIKRETE Concrete Mix 1101 yields: 40 lb = 0.30 ft³, 60 lb = 0.45 ft³, and 80 lb = 0.60 ft³. Divide the volume by the bag yield, then round up. Each bag size is an alternative, not a combined shopping list. A 10 × 10 ft slab, 4 inches thick, needs 112, 75, or 56 bags respectively before waste; with 10% extra, it needs 123, 82, or 62. Check the yield on your actual product. Material cost is volume times your price per cubic yard, including the allowance when selected. Delivery, labor, reinforcement, and formwork are excluded. Use the Online Calculator for other arithmetic or the Fraction Calculator for mixed measurements.