Question: how to calculate percentage from volume?
Answer: A percent v/v solution is calculated by the following formula using the milliliter as the base measure of volume (v): % v/v = mL of solute/100 mL of solution. Example: X % = 5.0 mL HCl/100 mL of solution. X/100 = 5.0/100. 100X = 500. X = 5.0% % v/v.