How to use this calculator
Choose the slab dimensions and units, enter thickness, and set a waste allowance. Add your supplier’s price if you want a material cost estimate. Reinforcement estimates require the number and length of pieces you actually plan to order.
Method and interpretation
Slab volume is length × width × thickness after converting all three dimensions to the same unit. Cubic feet convert to cubic yards by dividing by 27. The waste allowance increases the order volume; it does not change the geometric slab volume.
Assumptions and limits
The result is a volume and supplied-price estimate, not a structural design or a concrete mix recipe. Costs include the material price, labor hours and rate, delivery charge and reinforcement inputs you enter. Supplier minimums, pumping, site conditions and local code requirements are not determined automatically. Reinforcement spacing, bar size and load capacity must come from the project design rather than this calculator.
Worked example
A 10 ft by 10 ft slab that is 4 inches thick has volume 10 × 10 × (4/12) = 33.33 cubic feet, or approximately 1.235 cubic yards. Adding 10% waste gives about 1.358 cubic yards before supplier order rounding.