Construction
Concrete Ark Volume Calculator
Volume of a semicircular (arch) vault: half-cylinder approximation.
Free to use — no sign-up or login.
Volume
ft³
Volume
yd³
Amortization schedule
| # | Date | Payment | Principal | Extra | Interest | Balance |
|---|---|---|---|---|---|---|
This ark is a semicircular vault: half of π r² times the length. Radius 4 ft and length 20 ft give 502.65 ft³ (18.62 yd³).
A flat rectangle is on the concrete volume calculator.
The shape it actually computes
The solid is half a cylinder of radius r and length L. It is not a pair of walls plus a separate arch ring.
Same yard conversion
Cubic yards are cubic feet divided by 27, at two decimals.
Worked example: radius 4 ft
Radius 4 ft, length 20 ft. Volume 502.65 ft³ and 18.62 yd³.
\[ V = \tfrac{1}{2}\pi (4)^2 (20) \]
Frequently asked questions
What does the ark volume calculator measure?
A 4 ft radius and 20 ft length are 502.65 ft³ of half-cylinder.
How many decimal places does ark volume calculator show?
A 4 ft radius and 20 ft length are 502.65 ft³ of half-cylinder. Lengths, areas, volumes, and money use two decimals. Purchase counts are whole numbers.
Does ark volume calculator include waste?
No waste factor. The half-cylinder is the whole answer.
Can ark volume calculator mix units?
No. ark volume calculator expects every input in the unit printed on its label.
Is ark volume calculator a code or structural check?
No. ark volume 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 model is a half-cylinder vault, not a hollow shell.