Boneyard Tools

Mass Percent Calculator

Find the mass percent of a solute, also called percent by mass or weight percent. Enter the mass of solute and either the mass of solvent or the total mass of the solution, and the calculator returns the percentage.

How to calculate mass percent

  1. Enter the mass of solute in grams.
  2. Enter the solvent mass, or the total solution mass if you know it.
  3. Read the mass percent, computed from solute mass / solution mass times 100.

Examples

From solute and solvent

10 g solute, 90 g solvent
10% by mass

From a known solution mass

10 g solute in 200 g solution
5% by mass

Frequently asked questions

What is mass percent?

Mass percent is the mass of a solute divided by the total mass of the solution, multiplied by 100. It is also called percent by mass or weight percent.

What is the mass percent formula?

Mass percent equals the mass of solute divided by the mass of solution, times 100. The solution mass is the solute mass plus the solvent mass.

Should I use solvent mass or solution mass?

Either works. If you enter the solvent mass, the tool adds it to the solute to get the solution mass. Otherwise enter the total solution mass directly.

Do the units of mass matter?

No, as long as both masses use the same unit. Grams are typical, but the percentage is the same whether you use grams, kilograms or ounces.

Why is my result over 100 percent?

That means the solute mass is larger than the solution mass, which is impossible. Check that the solute is part of the solution total you entered.

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