Concrete Square Footage Calculator
Calculate concrete area in square feet, then convert to cubic yards based on slab thickness. Concrete is poured by volume but designed by area.
Concrete Area Calculator
From square feet to cubic yards
Concrete is ordered in cubic yards. To convert: (square feet × thickness in feet) ÷ 27. A 200 sq ft slab at 4 inches (0.33 ft) thick needs (200 × 0.33) ÷ 27 = 2.4 cubic yards. Round up to 2.5 yards when ordering.
Standard thicknesses: 4 inches for sidewalks and patios, 5–6 inches for driveways, 6 inches or more for vehicle pads with heavy loads.
Always overorder slightly
Concrete is unforgiving — when the truck leaves, that's what you've got. Always order 5–10% extra to account for grade variations, formwork bulge, and overpour.
Most ready-mix companies have a minimum order (usually 1 yard) and charge a "short load" fee for orders under 3–4 yards. For small slabs, bagged concrete may actually be cheaper.
Pro tips
Compact your base
A poorly-compacted gravel base will allow concrete to settle unevenly. Compact in 2-inch lifts before pouring.
Add reinforcement
Wire mesh or rebar is critical for any slab over 100 sq ft. It prevents cracks and extends slab life.
Plan for control joints
Saw-cut control joints every 8–12 ft prevent random cracking. Plan their location before pouring.
Consider weather
Don't pour concrete below 40°F or above 90°F without admixtures. Hot weather requires retarders; cold needs accelerators.