Construction
Concrete Round Slab Volume Calculator
Volume of a circular slab from diameter and thickness.
Free to use — no sign-up or login.
0.33 ft is about 4 inches.
Volume
ft³
Volume
yd³
Amortization schedule
| # | Date | Payment | Principal | Extra | Interest | Balance |
|---|---|---|---|---|---|---|
A round slab is a cylinder: area π r² times thickness. A 10 ft diameter means a 5 ft radius. At 0.33 ft thick the volume is 25.92 ft³ (0.96 yd³).
Thickness 0.33 ft is about 4 inches. A rectangular pour is on the concrete volume calculator.
Diameter, then radius
The field is diameter. The formula uses half of that as the radius. A 10 ft circle is not a 10 ft radius.
Cubic feet and cubic yards
Both volumes are the same pour. Cubic yards equal cubic feet divided by 27, shown to two decimals.
Worked example: 10 ft diameter
Diameter 10 ft, thickness 0.33 ft. Volume 25.92 ft³ and 0.96 yd³. The 0.33 ft thickness is about 4 inches.
\[ V = \pi (5)^2 (0.33) \]
Frequently asked questions
What does the round slab calculator measure?
It reports 25.92 ft³ for a 10 ft diameter and 0.33 ft thickness.
How many decimal places does round slab calculator show?
It reports 25.92 ft³ for a 10 ft diameter and 0.33 ft thickness. Lengths, areas, volumes, and money use two decimals. Purchase counts are whole numbers.
Does round slab calculator include waste?
No. Order extra if the site needs waste. The formula is the geometric volume only.
Can round slab calculator mix units?
No. round slab calculator expects every input in the unit printed on its label.
Is round slab calculator a code or structural check?
No. round slab calculator is a quantity estimate. Local rules and site conditions stay outside the formula.
References
Assumptions and limitations
No waste factor and no rebar. The slab is a flat cylinder, not a sloped or thickened-edge pour.