How to Measure the Volume of a Solid

A simple formula can tell you the volume of a solid object.

Measuring the volume of a solid object is the same as measuring the amount of space the object takes up. There are two different methods for measuring a solid object. The simplest method uses a simple mathematical formula to calculate the volume of a solid object with a regular shape, such as a cube or sphere. Another method uses water displacement to measure the volume of a solid object of irregular shape, such as a shell, a stone or a pair of eyeglasses.

Things You'll Need

• Ruler or measuring tape
• Calculator
• Graduated cylinder or measuring cup

Instructions

Measuring Regular Solids

1. Measure the object. For a rectangular object, measure length, width and height. For a sphere, measure the diameter. For a cylinder or cone, measure the diameter and height.

2. Find the relevant formula to calculate the volume. For the rectangular object, volume = height x width x length. For a sphere, the formula is: volume = 4/3 pi x radius cubed. For a cylinder, volume = pi x radius squared x height. For a cone, volume = 1/3 pi x radius squared x height.

3. Put your measurements into the appropriate formula and do the calculations to arrive at the theoretical volume of the object.

Measuring Irregular Solids

1. Fill a graduated cylinder or measuring cup halfway with water. Record the level of the water.

2. Place the irregular solid object into the water. Record the new level of the water.

3. Subtract the original amount of water from the new level of water, using a calculator if necessary. The resulting number is the volume of the irregular solid object.

References

• NASA's Kid Science News Network: What is Volume?
• Math and Science Activities Center: Volume
• Mr. Derringer: Measurement