Concrete Patio Calculator
Flat outdoor slab for entertaining spaces and grill pads.
Step 1: Units
Step 2
Enter project measurements
Use decimals if needed (e.g. 3.5).
Step 3
How to use this calculator
Use longest clear spans for length and width; depth is finished thickness.
What the math is doing
Volume = length × width × thickness.
Frequently asked questions
Slope for drainage?
Use average thickness if slope is gentle.
Stamps?
Surface area unchanged for volume.
Footings around edge?
Add footing prism separately.
Vapor barrier?
Area matches footprint.