Percent Solution Calculator
Calculate mass/volume, mass/mass, or volume/volume percentage with the denominator made explicit.
01 Set up your calculation
- Select the percentage definition used by the problem or label.
- Enter the solute amount and the final total solution amount.
- Read the percentage together with its w/v, w/w, or v/v qualifier.
02 The relationship
For the assumptions behind these results, read the explanation below. You can also explore Mass Percent and Percentage Concentration to Molarity.
Follow the numbers
5 g of solute made up to 100 mL final solution gives 5% w/v, equivalent to 50 g/L. That does not by itself establish 5% w/w.
03 The percent sign alone is incomplete
Three common percentage conventions answer different questions. Mass/volume states grams per 100 mL, mass/mass states grams per 100 g, and volume/volume states mL per 100 mL. Write the basis whenever the context does not make it unambiguous.
In each case the denominator describes the complete solution. For a 5% w/v preparation, adding 5 g to 100 mL of solvent is not necessarily equivalent to making the final solution up to 100 mL.
04 When the definitions can be compared
Converting mass percentage to mass/volume percentage requires solution density. Converting a liquid component’s mass to its volume also requires its density. Those extra properties cannot be inferred from the percent number alone.
A mass/volume percentage can numerically exceed 100 because grams and milliliters are different dimensions; it is a conventional concentration expression rather than a same-dimension fraction. The mass/mass and volume/volume fraction modes here are constrained to 0–100%.
Questions from the notebook
Does 0.9% w/v mean 0.9 g in 100 mL?
Yes: 0.9 g of solute per 100 mL of final solution.
Why do w/v results also show g/L?
Multiplying grams per 100 mL by ten gives grams per liter, a convenient mass-concentration unit.
Does the tool check whether the solute dissolves?
No. The percentage calculation is separate from solubility and preparation conditions.
References & reading
- OpenStax, Rice University — Other Units for Solution Concentrations ↗
Distinguishes mass, volume, mass-volume percentages and parts per million.
- NIST — Guide to SI conversion factors ↗
Supports physical unit conversions. Input values are converted to the formula’s base units before calculation.
Our explanations are written for ChemistryCalc. Read how we build and check our tools. These calculations are educational estimates where the underlying model requires assumptions.