Cubic yards
Cubic Yards Cylinder
Size up bulk volume in cubic yards for concrete, fill and large cylindrical forms, straight from feet or inches.
When you are ordering concrete or fill for a round column or footing, you think in cubic yards — and this cubic yards cylinder gets you there. Enter the diameter and depth, and read the yd³ figure you can take to the supplier.
Because a cubic yard is 27 cubic feet, the conversion is the easy part; the care goes into measuring the round form accurately and adding a margin for waste before you place the order.
The formula behind it
The volume of a cylinder is:
V = π r² hA worked example
Worked example. Take a cylinder with a diameter of 10 cm (so a radius of 5 cm) and a height of 25 cm. The base area is π × 5² = 78.54 cm², and multiplying by the height gives a volume of about 1.96 litres (1,963 cm³ · 0.52 US gallons).
| From | To | Multiply by |
|---|---|---|
| cm³ | litres | 0.001 |
| litres | m³ | 0.001 |
| in³ | US gallons | ÷ 231 |
| ft³ | US gallons | 7.4805 |
| ft³ | litres | 28.3168 |
For anything that holds liquid, measure the inside of the cylinder — the wall takes up space that the contents cannot.
Conversions use standard factors: 1 US gallon = 231 in³, 1 Imperial gallon = 4.54609 L, 1 litre = 1000 cm³.
How to work it out
- Measure across the circular end — the diameter or radius.
- If you measured the diameter, halve it to get the radius r.
- Square the radius and multiply by π to get the base area.
- Multiply the base area by the height h: V = π r² h.
- Convert the result into your preferred unit above.
Getting an accurate measurement
If you can only reach the top, measure the diameter across the opening and halve it. Keep every measurement in the same system, and let the tool convert between units for you.
Follow-on questions, answered
The figure above is usually the start, not the finish. These are the questions that tend to come next, answered here so you do not have to run another search:
What is it in cubic metres?
One cubic yard is about 0.765 cubic metres, shown alongside the result for metric suppliers.
Do I measure the form in feet or inches?
Either works. Enter inches if that is how the round form was measured and the tool converts to feet, then to cubic yards, before you order.
How many cubic feet is that?
One cubic yard is 27 cubic feet, and the cubic-foot value appears in the breakdown, so you can cross-check a concrete order both ways.
How much ready-mix should I order?
Round columns and footings are priced by the cubic yard; it is normal to add about 5 to 10 percent on top of the geometric figure for spillage and uneven ground.
Common mistakes to avoid
The commonest slip is using the diameter where the formula wants the radius, which on its own quadruples the base area. Close behind is mixing units, such as a radius in centimetres with a height in metres. Keep every length in the same unit, or let the tool convert, and double-check whether you measured to the centre or across the whole width. When a figure looks surprising, that width measurement is almost always where the problem is hiding, so re-read it first.
One result, every unit
One number, many units. Whatever you enter, the result lists the same volume as litres, US gallons, Imperial gallons, millilitres, cubic centimetres, cubic inches, cubic feet, cubic yards and cubic metres at the same time. You almost never have to convert by hand: read the figure in the unit your job uses and copy any of the others straight from the breakdown. If you need a shareable version, the copy-link button preserves your exact inputs so a colleague opens the page with the same calculation already filled in.
Keep going
Once you have your answer you may also want to work in cubic feet tank capacity gallons. These related calculators pick up where this one leaves off:
When this comes in handy
People reach for this in a range of situations:
- Ordering ready-mix for cylindrical piers
- Estimating fill for round forms
- Bulk material planning on a job site
The bottom line: with the radius or diameter and the height, the volume follows immediately, and the breakdown lets you hand the same number to anyone in the unit they prefer. Measure inside dimensions for anything that holds liquid, leave a little headspace at the top of a real container, and treat the geometric figure as a clean maximum rather than the final word on usable capacity.
Questions people ask
Does this work for a tank or a pipe?
What is the formula for the volume of a cylinder?
V = π r² h — the area of the circular base (π r²) multiplied by the height (h). If you have the diameter instead of the radius, halve it first: r = d ÷ 2.