How to Figure the Volume of a Cylinder

We often need to be able to determine the volume of an object in order to know how much material it will hold. Many such objects such as glasses and buckets are of a cylindrical design and can easily have their volume calculated by using the formula V = πhr^2 where h is the height of the cylinder and r denotes the radius of the base.

Things You'll Need

• Paper
• Pen or Pencil
• Ruler or tape measure
• Calculator (optional)

Instructions

1. Determine the radius and height of the cylinder with a ruler or tape measure. Make sure that you use the same units for both measurements. That is, if you measure the radius of the base in inches, then measure the height of the cylinder in inches as well. As an example, suppose that we have a cylindrical sand bucket 10 inches tall with a radius of 2 inches, and we want to determine how much sand it will hold.

2. Multiply your measurements using the formula V = πhr^2. In our example we would obtain V = π * 10 * 4 = 40π.

3. Use a calculator and the fact that π is approximately 3.1416 to obtain a decimal estimation of your answer. Our example would yield the result 125.664.

4. Apply the measurements to your final answer. Volume is measured in cubic units. Since our example involved inches, our final answer would be 125.664 cubic inches.

Tips & Warnings

• Even if the object you are trying to calculate the volume of is not a perfect cylinder, you can still estimate the volume of the object by using this formula.

• Don't forget to measure the height of your cylinder and the radius of your base in the same units.