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Mass Percent Calculator

Mass percent calculator

Compute mass-percent concentration (w/w%) from solute and total solution mass.

InputsChemistry2 fieldsLive

Result

5% w/w

Uses mass% = (solute mass / solution mass) × 100.

Live update

Chem signal

Advanced options
Flow
  • Enter solute mass and total solution mass.
  • Verify that solution mass is larger than solute mass.
  • Read concentration as w/w percent.
Example

Worked example: 12.5 g solute in 250 g solution

  1. 1 Divide solute mass by total solution mass.
  2. 2 Multiply by 100 for percent scale.
  3. 3 12.5/250 × 100 = 5.

Mass percent is 5.0% w/w.

How
  1. Enter solute mass and total solution mass.
  2. Verify that solution mass is larger than solute mass.
  3. Read concentration as w/w percent.
Avoid
  • Using solvent mass instead of total solution mass.
  • Mixing volume-based percentages with mass-percent equations.
Checks

Best fit

Mass Percent Calculator is built for compute mass percent concentration (w/w) from solute mass and total solution mass. If Mass Percent Calculator does not match the input scope, compare the answer with a second method.

Input check

Match the entered values to this rule before copying the answer: mass% = (mass of solute / mass of solution) × 100.

Sanity check

For Mass Percent Calculator, use the worked example as a quick benchmark: Mass percent is 5.0% w/w. If the mass percent calculator answer is far away, check whether an input, unit, or mode changed.

Before copying

Review this common issue first: using solvent mass instead of total solution mass.

Ref only. Verify values. Follow lab safety.

FAQ
Is this the same as mass fraction?

Mass fraction is decimal form; mass percent is mass fraction × 100.

Can solute mass exceed solution mass?

No. That would be physically inconsistent for this definition.

Can I use kilograms instead of grams?

Yes, as long as both masses use the same unit.

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