How to Calculate Volume

You can find the volume of various 3-D objects using a few simple mathematical formulas.

You will need

  • Object to be measured
  • Geometric formulas
  • Water
  • Graduated cylinder

Step 1 Consider a rectangular or cubic solid Consider a rectangular or cubic solid. Measure the length, width, and height of the object. Multiply these dimensions together to get the volume.

Step 2 Look at a cylindrical object To find the volume of a cylinder, multiply the square of its radius by pi, or 3.14. Then multiply this value by the height of the cylinder.

Step 3 Calculate the volume of a cone Calculate the volume of a cone. Measure the area of the cone’s base — pi times the radius squared — then multiply by the height and divide by 3.

Step 4 Measure a sphere Measure the radius of a sphere, then calculate the volume by multiplying 4/3 times pi times the cube of the radius.

Step 5 Use water displacement Place a solid object whose volume is to be measured in a graduated cylinder that has been partially filled with water. Measure the amount of water displaced by the object — this is the object’s volume.