Percentage to Molarity Calculator

Convert weight percentage concentration to molar concentration.

Solution Properties

Percentage Concentration (% w/w)

Density (ρ)

g/mL

Molar Mass (MW)

g/mol

Result

Enter density and molar mass to see conversion results

Overview

Many commercial chemical solutions are labeled with weight percentage and density rather than molarity. This calculator converts these common laboratory specifications to molar concentration (moles per liter), which is essential for accurate stoichiometric calculations and solution preparation. The conversion accounts for the solution's density to determine how many grams of solute are present per liter.

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Pro Tips

Percentage is weight/weight (% w/w) - the mass of solute per 100g of solution.
Density units should be g/mL (multiply kg/L by 0.001 to convert or leave as is if numerically identical).
The factor '10' is a simplification of (1000 mL/L) / (100% base).
For dilute aqueous solutions, the density is often close to 1.00 g/mL.
Always double-check if the label is % w/w or % w/v (weight/volume). This calculator is for % w/w.

Fun Facts

"Concentrated hydrochloric acid (37% w/w) has a molarity of about 12 M and can dissolve metals rapidly."
"Concentrated sulfuric acid (98% w/w) is approximately 18.4 M and is extremely dehydrating."
"Glacial acetic acid is nearly pure (99.7% w/w) and freezes at 16.6°C, forming crystals that look like ice."
"Household vinegar is typically 5% w/w acetic acid, which is roughly 0.83 M."
"The world's strongest acids, known as superacids, are often measured in molarity that exceeds 20 M."

Formula: M = (Percentage × Density × 10) / Molar Mass

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