You can calculate the volume of a cone easily once you know its height and radius and can plug those measurements into the formula for finding the volume of a cone. The formula for finding the volume of a cone is v = hπr2/3.[1]

Method 1
Method 1 of 1:

Calculating the Volume of a Cone

  1. 1
    Find the radius. If you already know the radius, then you can move on to the next step. If you know the diameter, divide it by 2 to get the radius.[2] If you know the circumference, divide it by 2π to get the diameter.[3] And if you don't know any of the measurements of the shape, just use a ruler to measure the widest pie circular base (the diameter) and divide that number by 2 to get the radius. Let's say the radius of this cone's circular base is .5 inches (1.3 cm).
  2. 2
    Use the radius to find the area of the base circle. To find the area of the base circle, you can just use the same formula you'd use to find the area of a circle: A = πr2. Plug ".5" in for r to get A = π(.5)2 and square the radius and multiply it by the value of π to find the area of the circular base. π(.5)2 = .79 in.2.[4]
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  3. 3
    Find the height of the cone. If you know it already, write it down. If you don't know it, use a ruler to measure it.[5] Let's say the height of the cone is 1.5 inches (1.3 cm). Make sure that the height of the cone is written in the same measurements as the radius.
  4. 4
    Multiply the area of the base by the height of the cone. Multiply the area of the base, .79 in.2, by the height, 1.5 in. So, .79 in.2 x 1.5 in = 1.19 in.[6] 3
  5. 5
    Divide the product by three. Simply divide 1.19 in.3 by 3 to find the volume of a cone. 1.19 in.3/3 = .40 in.3. Always state the volume in cubic units because it's a measure of three-dimensional space.[7]
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Community Q&A

  • Question
    What if the given is slant height and base? How to find the volume of cone?
    Community Answer
    Community Answer
    Use the Pythagorean Theorem to find the height, using the slant length as the hypotenuse and half the base as one side.
  • Question
    How do I calculate the radius of a cone when I already have the volume?
    Community Answer
    Community Answer
    You would do: V = 1/3 *π*r^2. Divide volume by 3. Divide volume by π, then square root that number. And there is your radius.
  • Question
    If I double the height, will I double the volume?
    Donagan
    Donagan
    Top Answerer
    Yes.
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About This Article

wikiHow is a “wiki,” similar to Wikipedia, which means that many of our articles are co-written by multiple authors. To create this article, 52 people, some anonymous, worked to edit and improve it over time. This article has been viewed 889,951 times.
72 votes - 70%
Co-authors: 52
Updated: February 14, 2023
Views: 889,951
Categories: Volume
Article SummaryX

To calculate the volume of a cone, start by finding the cone's radius, which is equal to half of its diameter. Next, plug the radius into the formula A = πr^2, where A is the area and r is the radius. Once you have the area, multiply it by the height of the cone. Finally, divide that number by 3 to find the volume of the cone. Remember to write your answer in cubic units. For helpful sheets you can print out and take with you, read on!

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