How to Convert Displaced Water to Volume

Choose a graduated cylinder large enough to hold the object being measured.

Finding the volume of a regular three-dimensional object, such as a cube with 2-inch sides, is straightforward and involves multiplying the length by the width by the height. With an irregularly shaped object, the formula for volume is not readily apparent. Water displacement is a useful method for calculating the volume of a solid object with an irregular shape. The amount of water displaced by the object is equal to the volume of the object. This measurement in milliliters can then be converted to cubic inches using a conversion formula.

Things You'll Need

• Graduated cylinder
• Water
• Solid object

Instructions

1. Fill the graduated cylinder with enough water to completely submerge the solid object without causing the water to overflow. Record the starting volume of water, or level A, by writing down the measurement shown on the cylinder.

2. Gently submerge the solid object. Record the new water level, or level B, by writing down the new measurement shown on the cylinder.

3. Find the amount of water displaced by subtracting level A from level B. Record the result in milliliters:

   b - a = displaced water

4. Convert the volume in milliliters to cubic inches using the following conversion rule: Divide the number of milliliters, or cubic centimeters, by 16.387. For example, if your displacement was 20 milliliters, you would divide by 16.387 to obtain a measurement of 1.22 cubic inches.

Tips & Warnings

• Make certain that the object is fully submerged in the water. Otherwise, your displacement will not be accurate.

References

• Fordham Preparatory School: Water Displacement Method
• Convert Units: Convert ml to Cubic Inch