What are you working on?
Choose a project to get started. You can change it anytime.
Simple guidance for your home project.
Let’s figure out your concrete
Order allowance
Plan your deck materials
Surface-material planning only. This is not a structural deck design, permit plan, or footing/post sizing calculation.
Hit me with the measurements
Curious how we did the math? (optional)
Open this only if you want to review assumptions or fine-tune coverage rates. Most users can leave the defaults as they are.
Estimator assumptions
These are preliminary quantity estimates, not construction documents or purchasing guarantees. Actual quantities depend on layout, manufacturer coverage, seams, patterns, direction, substrates, and field conditions.
How it works
How to get a good estimate
- Choose the concrete shape or Stone / gravel calculator.
- Measure the dimensions and enter them in the units shown.
- Choose an allowance for uneven ground, spillage, and measurement uncertainty.
- Use the result as a planning number, then confirm the order with your ready-mix supplier.
How are concrete and stone quantities calculated?
Slabs: length × width × thickness, converted to cubic feet. Rectangular footings: length × width × depth. Round columns: π × radius² × height, multiplied by the number of columns. Stone / gravel: area length × area width × depth, then converted to cubic yards and estimated tons using the selected tons-per-yard assumption. Cubic feet are divided by 27 to convert to cubic yards.
Concrete bag counts are rough equivalents based on typical nominal yields (80 lb ≈ 0.60 ft³, 60 lb ≈ 0.45 ft³, 40 lb ≈ 0.30 ft³). Stone tonnage is approximate: the actual tons per cubic yard depend on aggregate type, gradation, and moisture. Confirm with your local supplier.
Check the product label and double-check your measurements before buying. We do math; we do not bend the laws of physics.