Concrete Calculator
Estimate concrete volume for footings, slabs, and round piers.
Switch between rectangular and round pours, add waste, and optionally convert the result into 60 lb or 80 lb bag counts.
Material ListPour shape
Switch between slab and footing rectangles or round piers.
Dimensions
Type a plain number in feet, or tape-measure notation like 10' 6-3/4".
Mix ratio
Optional — enter all three parts (e.g. the standard 1:2:4 cement:sand:gravel) to break the total volume into component volumes. Leave any part blank to skip.
Rebar grid
Optional — enter a spacing and bar size to compute a rebar grid's linear footage and weight for this rectangular pour.
Order 0.41 cu yd of concrete for this pour.
Order
Concrete estimate
Warnings
- INFO Material estimate only. Footing depth, size, reinforcement, frost depth, and bearing capacity must be verified locally.
Detail values
- Cubic feet
- 10
- Cubic yards
- 0.37
- Waste-adjusted cubic yards
- 0.41
- Bag count
- 21
- Effective depth (incl. frost line)
- 0.5 ft
Assumptions
- Concrete density for bag estimate: 4050 lb per cubic yard
- Bag mode enabled: Yes
Included: concrete volume, waste allowance.
Not included: labor, delivery, permits, disposal, compaction (enter your intended post-compaction depth/volume — this estimate does not account for compaction itself), rebar and forms.
Formula details
- Rectangular volume: length x width x depth
- Round volume: pi x radius^2 x depth
- Cubic yards: cubicFeet / 27
- Bag count: ceil((wasteAdjustedCubicYards x 4050) / bagSize)
FAQ
Can I estimate sonotube piers here?
Yes. Use the round mode, enter diameter and depth, and the calculator returns cubic feet, yards, and optional bag counts.
Why is there a local verification warning?
Concrete quantity alone does not verify footing design, reinforcement, frost depth, or bearing capacity.
Are bag counts based on waste-adjusted volume?
Yes. The bag estimate uses the waste-adjusted cubic-yard total before rounding up to full bags.
Disclaimer
Material estimate only. Footing depth, size, reinforcement, frost depth, and bearing capacity must be verified locally.