semkuCylinder volume calculator
Enter a radius or diameter and a height to calculate cylinder volume.
Calculation rules
Cylinder volume is V = πr²h. When you enter a diameter, the radius is half that diameter; zero radius or height gives zero volume.
Unit conversions use exact definitions: 1 in = 2.54 cm, 1 ft = 12 in, 1 m³ = 1,000 L and 1 US gal = 231 in³. Gallons here are US liquid gallons.
π is approximated to 40 decimal places. Results are rounded once from the unrounded calculation: the selected cubic unit to two decimal places, liters and US gallons to three, and the additional ft³ and m³ conversions to six, with ties rounded away from zero. A positive value that would round to zero is shown as less than the smallest displayed unit.
Pipe mode calculates the internal volume of one full, round pipe: V = π × (inner diameter / 2)² × length. Use the selected length unit for both measurements.
Water weight is mass: kilograms = density in kg/m³ × volume in m³; pounds = kilograms / 0.45359237. No water density is prefilled. Each mass result is rounded once from its unrounded value to three decimal places, with ties rounded away from zero. A positive mass that would round to zero is shown as less than 0.001 kg or lb.
Frequently asked questions
- What is the volume for a radius of 3 in and a height of 10 in?
- The volume is 90π in³, displayed as 282.74 in³, 4.633 L or 1.224 US gal.
- Can I enter diameter instead of radius?
- Yes. Choose Diameter; the calculator divides it by two before applying V = πr²h.
- Are the gallons US or imperial gallons?
- They are US liquid gallons, defined as 231 cubic inches per gallon.
- Does this calculate a hollow cylinder?
- Cylinder mode calculates a solid cylinder's volume. Pipe mode uses inner diameter and length to calculate the space inside a full, round pipe. It does not calculate the volume of the pipe wall or a partly filled pipe.
- How do I calculate the weight of water in a pipe?
- Choose Pipe, enter its inner diameter and length, then enter water density in kg/m³ for the relevant temperature and pressure. The result gives water mass in kg and lb. With density left blank, only volume is calculated.
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Calculations run in your browser without sending your calculation inputs or results to the server. See “Privacy on this page” for information about access data.