ConcreteCalc
PRO All 30 Tools
All 30 Tools

Concrete Yard Calculator

To calculate concrete cubic yards: multiply Length (ft) × Width (ft) × Thickness (in) / 12 to get cubic feet, then divide by 27. Always add a 10% waste buffer for slab grade variations and formwork deflection. One cubic yard equals 27 cubic feet, yields about 45 bags of 60-lb concrete (or 33.75 bags of 80-lb concrete), and weighs approximately 4,050 lbs.

Interactive Concrete Yard Calculator

ENGINEERING SCHEMATIC
1 Cubic Yard Reference Volume (3ft × 3ft × 3ft)
Volume (V) = Area × Depth 1 Cubic Yard = 27 Cubic Feet
💡
Pro Contractor Recommendation: One cubic yard measures exactly 3 ft by 3 ft by 3 ft (27 cubic feet). At 4" thickness, 1 cubic yard covers 81 square feet.
Project Dimensions
Waste Allowance & Cost Estimate
$
Total Concrete Yardage Required
2.72 Cubic Yards (yd³)

Includes 10% waste buffer (Net: 2.47 yd³)

Cubic Feet & Meters
73.3 cu ft
2.08 m³
80 lb Pre-Mix Bags
123 bags
Yield ~0.60 cu ft/bag
60 lb Pre-Mix Bags
163 bags
Yield ~0.45 cu ft/bag
Ready-Mix Truck Loads
0.27 loads
Based on 10 yd³ truck
Estimated Ready-Mix Cost
$ 407.41
At $150 / cubic yard

How to Calculate Concrete Yardage

Ready-mix concrete suppliers sell bulk concrete by the cubic yard (often shortened to "yard"). A cubic yard is a cube measuring 3 feet (1 yard) on each side, having a volume of 3 × 3 × 3 = 27 cubic feet.

Standard Slab Yardage Formula

Cubic Yards = (Length [ft] × Width [ft] × Thickness [ft]) ÷ 27

If thickness is measured in inches:

Cubic Yards = (Length [ft] × Width [ft] × (Thickness [in] ÷ 12)) ÷ 27

Cubic Yard Coverage Table (At Common Thicknesses)

Slab Thickness Thickness in Feet Square Feet Covered per 1 Cubic Yard
3 inches 0.25 ft 108 sq ft
4 inches (Standard Patio/Sidewalk) 0.333 ft 81 sq ft
5 inches (Heavy Driveway) 0.417 ft 65 sq ft
6 inches (Garage / RV Pad) 0.50 ft 54 sq ft
8 inches (Commercial Footing) 0.667 ft 40.5 sq ft

Should You Order Ready-Mix or Mix Bags?

As a general contractor rule of thumb:

  • Under 1 Cubic Yard (under 45 60-lb bags): Mixing dry pre-mixed bags in a rental barrel mixer or wheelbarrow is cost-effective for small pads, post holes, and minor repairs.
  • Over 1 Cubic Yard: Ordering a ready-mix concrete transit truck is substantially faster, ensures uniform compressive strength, and avoids the extreme physical labor of hand-mixing thousands of pounds of concrete. Keep in mind most ready-mix suppliers charge a short-load fee for orders under 4 to 5 cubic yards.