Cubic Yards Cylinder Calculator

Background.

Ready-mix trucks, landscape suppliers and gravel yards in the US sell by the cubic yard, but round things get measured in feet and inches: a column form 12 inches across, a planter 4 feet wide, a tank 6 feet in diameter. Getting from one to the other takes two steps that are easy to fumble on a job site — the area of a circle, then a division by 27.

The circle causes most of the trouble. Its area is π times the radius squared, and the radius is half the diameter, so plugging in the full diameter by mistake produces four times too much material. The squaring also means width dominates. A round pad 12 feet across and 3 feet deep holds four times as much as one 6 feet across, while doubling the depth merely doubles it.

Then comes the unit. A yard is 3 feet, so a cubic yard is 3 × 3 × 3 = 27 cubic feet — not 3, and not 9. Dividing by the wrong one leaves a delivery a fraction of what the job needs, or several times too big.

Typical uses are round concrete columns and pier footings poured into cardboard tube forms, soil for a circular raised bed or planter, gravel for a round base, and the capacity of an upright tank. The answer is the plain geometric volume of a right cylinder, with straight sides and flat ends square to them. It adds nothing for spillage, an uneven hole, or soil and gravel that settle once compacted, so order with a margin.

What is cubic yards cylinder calculator?

A cylinder's volume is the space enclosed by two identical circular ends and the straight wall joining them. For a right cylinder, whose wall stands perpendicular to the ends, it equals the area of one end multiplied by the height. Measured in feet, that gives cubic feet; dividing by 27 converts the result to cubic yards, the unit in which ready-mix concrete, topsoil, mulch and gravel are usually sold in the US. One cubic yard is about 0.765 cubic metres.

How to use this calculator.

1. 01Measure the diameter straight across the circle through its centre and enter it in feet. Divide inches by 12: a 12-inch tube form is 1 ft, an 8-inch form about 0.667 ft.
2. 02If you cannot reach across, wrap a tape around the outside and divide that circumference by 3.1416 to get the diameter — 18.85 ft around is about 6 ft across.
3. 03Enter the height in feet: the depth of the hole for a footing, or the depth of soil you plan to add for a planter rather than the full height of the pot.
4. 04Read cubic yards for a bulk order and cubic feet for bagged material, dividing by the yield printed on the bag. Multiply by the number of identical columns or footings, then add a margin.

The formula.

Volume (yd³) = π × (d ÷ 2)² × h ÷ 27. Here d is the diameter and h the height, both in feet. Halving the diameter gives the radius; squaring it and multiplying by π, about 3.14159, gives the area of the circular end in square feet. Multiplying by the height turns that area into cubic feet. Dividing by 27 — the exact number of cubic feet in a cubic yard, since a yard is three feet — gives cubic yards. Because the diameter is squared, it has by far the stronger influence: a diameter measured 10% too large inflates the volume by 21%, while a height 10% too large inflates it by only 10%. Both measurements must be greater than zero, and the formula assumes the sides are vertical and the diameter is the same from top to bottom.

A worked example.

Frequently asked questions.

References& sources.

1. [1]National Institute of Standards and Technology. NIST SI Guide, 2008 edition. Appendix B unit relationships. Retrieved 2026-08-06.
2. [2]OpenStax, Rice University. Precalculus 2e, 2021. Trigonometry and analytic geometry chapters. Retrieved 2026-08-06.
3. [3]NIST/SEMATECH. e-Handbook of Statistical Methods, 2012. Chapter 1.3 and Chapter 4. Retrieved 2026-08-06.