Cylinder Volume Calculator

Calculate cylinder volume from radius or diameter and height, with litres, cubic metres, cubic feet and optional allowance shown for tanks, tubes, posts and classroom work.

Cylinder volumeCylinder Volume Calculator uses the declared inputs to produce a transparent default result. Diameter: 1.2 metres; Radius override: 0 metres; Height / length: 2 metres; Allowance: 5 percent; primary comparison: 1.2 and 0.

DiametermetresRadius overridemetresHeight / lengthmetresAllowancepercent

Live math canvas

Your numbers, formula and explanation together

Cylinder Volume Calculator: 8.2 cubic metres and litres. Cylinder Volume Calculator uses the declared inputs to produce a transparent default result. Diameter: 1.2 metres; Radius override: 0 metres; Height / length: 2 metres; Allowance: 5 percent; primary comparison: 1.2 and 0.

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Cylinder volume = π × radius² × height. If diameter is entered, radius = diameter ÷ 2. Litres = cubic metres × 1,000. Optional planning volume = measured volume × (1 + allowance percent ÷ 100).

Apply the formulaCylinder volume = π × radius² × height. If diameter is entered, radius = diameter ÷ 2. Litres = cubic metres × 1,000. Optional planning volume = measured volume × (1 + allowance percent ÷ 100).8.2 cubic metres and litresCylinder Volume Calculator uses the declared inputs to produce a transparent default result. Diameter: 1.2 metres; Radius override: 0 metres; Height / length: 2 metres; Allowance: 5 percent; primary comparison: 1.2 and 0.

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

Diameter: 1.2 metres
Radius override: 0 metres
Height / length: 2 metres
Allowance: 5 percent

Resulting answer

8.2 cubic metres and litres

Cylinder Volume Calculator uses the declared inputs to produce a transparent default result. Diameter: 1.2 metres; Radius override: 0 metres; Height / length: 2 metres; Allowance: 5 percent; primary comparison: 1.2 and 0.

Answer: 8.2 cubic metres and litres
Live support: Cylinder Volume Calculator uses the declared inputs to produce a transparent default result. Diameter: 1.2 metres; Radius override: 0 metres; Height / length: 2 metres; Allowance: 5 percent; primary comparison: 1.2 and 0.

Assumptions used

What this answer assumes

For tank capacity, use internal dimensions and keep headspace or safety margin visible in the printed notes.

The cylinder is treated as a straight circular cylinder with flat circular ends.
Radius and height must use the same length unit; the default inputs use metres.
The allowance is shown as planning volume only and is not part of the exact geometric cylinder.
Horizontal tanks, domed ends, sloped cylinders, wall thickness and partial fill levels need specialist tank geometry or manufacturer data.

Master’s Tip

How to use the result well

Master’s Tip: measure the internal diameter when you need capacity. External diameter is useful for clearance and fabrication, but wall thickness can make the real internal volume noticeably smaller.

Printable record

What belongs in the saved calculation

Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.

Diameter: 1.2 metres
Radius override: 0 metres
Height / length: 2 metres
Allowance: 5 percent

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Formula

Cylinder volume = π × radius² × height. If diameter is entered, radius = diameter ÷ 2. Litres = cubic metres × 1,000. Optional planning volume = measured volume × (1 + allowance percent ÷ 100).

Worked example

Diameter 1.2 m gives radius 0.6 m. Volume = π × 0.6² × 2 = 2.2619 m³. That is 2,261.9 litres. With a 5% allowance, the planning volume is 2.3749 m³, or about 2,374.9 litres.

Professional note

Regional and unit assumptions

Standard or basis: Euclidean cylinder geometry using SI metre and litre display. One cubic metre equals 1,000 litres; cubic feet are shown as a secondary comparison using the international foot relationship.

Assumptions and limitations

The cylinder is treated as a straight circular cylinder with flat circular ends.
Radius and height must use the same length unit; the default inputs use metres.
The allowance is shown as planning volume only and is not part of the exact geometric cylinder.
Horizontal tanks, domed ends, sloped cylinders, wall thickness and partial fill levels need specialist tank geometry or manufacturer data.

Methodology & Accuracy

How this calculator is checked

CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.

Formula used

Standard or basis

Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.

Master's Tip

Questions

How do you calculate cylinder volume?

Square the radius, multiply by pi, then multiply by the height: volume = π × r² × h.

Can I use diameter instead of radius?

Yes. Enter the diameter and leave the radius override at zero. The calculator uses radius = diameter ÷ 2.

What unit is the result in?

The main result is cubic metres with litres shown beside it. Cubic feet are also shown as a secondary reference.

Is this suitable for a tank?

It works for a simple straight cylindrical tank when the full internal diameter and length are known. Domed ends, wall thickness and partial fill levels need a more specific tank calculation.

Why is the allowance separate?

The measured cylinder volume is geometry. Allowance is a planning assumption for headspace, waste or ordering margin, so it should not be mixed into the exact volume.

Calculation note

Cylinder volume is one of the most useful bridge formulas between classroom geometry and real measurement. It appears in tanks, pipes, drums, concrete cores, posts, silos, cans and tubes because many manufactured objects use circular cross-sections.

A cylinder is area carried through a length

The formula is easier to trust when it is read in two parts. First find the circular end area with π × radius². Then carry that same area through the height or length of the cylinder. That gives cubic units because a square-unit area is extended through a linear distance.

Diameter is often easier to measure than radius

On a real tank, pipe or tube, people usually measure straight across the opening. The calculator accepts diameter first because that matches tape-measure practice, then converts it to radius internally before applying the formula.

Capacity and outside size are not always the same

A pipe or tank can have a large outside diameter but a smaller internal capacity because of wall thickness, liners, domed ends, fittings or unusable headspace. The printable report keeps the dimensions, formula and allowance visible so those assumptions can be checked before ordering, filling or quoting.

Sources and further readingNIST: Guide for the Use of the International System of Units Wolfram MathWorld: Cylinder