Chemistry

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Mass Percent Calculator.

Calculate solute mass percentage from solute and total masses.

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01

Set your values

Results update as you type.

Mass fraction: 0.05

Mass fraction

0.0500
Mass percent: 5 %

Mass percent

5.0000%

Educational arithmetic only. Keep units consistent and use measured or explicitly supplied chemistry inputs; this tool does not infer reaction pathways, property tables, or safety guidance.

Use Cases

Lab Solution Preparation

Determine the concentration of a solution you've made by weighing the solute and measuring the total mass.

Example: Dissolve 5 g of salt in 95 g of water to get a 5% salt solution.

Homework and Exam Practice

Quickly verify mass percent calculations for chemistry assignments or test preparation.

Example: Check that 20 g solute in 80 g solution gives 25% mass percent.

Frequently Asked Questions

How do I calculate mass percent?
Enter the solute mass and the total mass of the solution (solute plus solvent). The calculator divides the solute mass by the total mass and multiplies by 100 to give the mass percent.
What units should I use for solute and total mass?
Use any consistent mass units, such as grams, kilograms, or milligrams. Both inputs must be in the same unit for the percentage to be correct.
Can I use this calculator for any type of solution?
Yes, as long as you know the mass of the solute and the total mass of the solution. It works for solid-liquid, liquid-liquid, or gas mixtures, provided you have the masses.

Tips & Common Mistakes

Tips

  • Ensure both masses are in the same unit before calculating.
  • Total mass is the sum of solute and solvent masses, not just the solvent.
  • Mass percent is independent of temperature and pressure, unlike volume-based concentrations.
  • Use the result to compare concentrations of different solutions.

Common Mistakes to Avoid

  • Using the solvent mass instead of the total solution mass in the denominator.
  • Forgetting to multiply by 100 to get a percentage.
  • Mixing units, like grams for solute and kilograms for total mass.

Last updated: August 13, 2026