Chemistry
Percentage Concentration to Molarity Calculator
Convert a mass-percentage solution strength into molarity using the solution density.
Your inputs
Change any value to update the result instantly.
Molarity
11.9748 mol/L
Mass of solute per litre
436.6 g/L
Mass of one litre of solution
1,180 g
Back-check: percentage from molarity
37 %
The percentage must be by mass (w/w) and the density must be for the solution, not the pure solute.
What this calculator does
Converts a mass-percentage solution strength into molarity using the solution density and the solute molar mass.
What your result means
The moles of solute in one litre of the solution as supplied, which is how concentrated reagents are usually labelled.
Formula and working
M = (% w/w × ρ × 10) ÷ M_r
- 1
Collect the inputs
Concentration by mass (% w/w) = 37 %; Density of the solution (ρ) = 1.18 g/mL; Molar mass of the solute (M_r) = 36.46 g/mol
- 2
Apply the formula
M = (% w/w × ρ × 10) ÷ M_r
- 3
Result
Molarity = 11.9748 mol/L
Frequently asked questions
Symbols and assumptions
- M
- Molarity in mol/L
- rho
- Solution density in g/mL
- M_r
- Molar mass in g/mol
- • The percentage is by mass (w/w).
- • The density is that of the solution, not the pure solute.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Using a w/v percentage or the solute density in place of the solution density gives a wrong answer.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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