Weight by volume is an easy way to express the concentration of a solution. It is calculated by dividing the mass in grams of the solute -- or what is dissolved in the liquid -- by the volume in milliliters of the whole solution. Weight by volume is usually abbreviated as w/v and expressed as a percentage.
Example w/v Calculation
Suppose you want to express the concentration of a sucrose -- table sugar -- solution you are making in w/v. If you created a 750-milliliter solution by adding 150 grams of sucrose to water, the w/v calculation would look like the following:
150 g / 750 mL = .20 or 20% w/v sucrose
Another example could be if you created a 200 mL solution by dissolving 57.0 grams of salt in water. The calculation would look like the following:
57.0 g / 200 mL = .285 or 28.5% w/v salt