Molarity to Percent Solution Calculator
Molarity to percent and back in % w/v, % w/w or % v/v, from the molar mass and a density where needed, with g/L and presets for stock acids and ethanol. How it works
Use the Molarity to Percent Solution Calculator
About the Molarity to Percent Solution Calculator
% w/v = molarity × molar mass ÷ 10. A 1.0 M NaCl solution (58.44 g/mol) holds 58.44 g per liter, which is 5.844 % w/v. For % w/w, divide by the solution density as well: % w/w = molarity × molar mass ÷ (10 × density in g/mL).
1 M solutions as % w/v
| Solute | Molar mass (g/mol) | 1 M as % w/v | 1 % w/v as molarity |
|---|---|---|---|
| Sodium chloride (NaCl) | 58.44 | 5.844 | 0.171 M |
| Sodium hydroxide (NaOH) | 40.00 | 4.000 | 0.250 M |
| Hydrochloric acid (HCl) | 36.46 | 3.646 | 0.274 M |
| Sulfuric acid (H₂SO₄) | 98.08 | 9.808 | 0.102 M |
| Glucose (C₆H₁₂O₆) | 180.16 | 18.016 | 0.056 M |
| Sucrose (C₁₂H₂₂O₁₁) | 342.30 | 34.230 | 0.029 M |
| Ethanol (C₂H₅OH) | 46.07 | 4.607 | 0.217 M |
| Acetic acid (CH₃COOH) | 60.05 | 6.005 | 0.167 M |
| Ammonia (NH₃) | 17.03 | 1.703 | 0.587 M |
Molar masses are the ones in the calculator’s compound list, rounded to two decimals (the Molar Mass Calculator gives sulfuric acid as 98.07). % w/v scales with molarity, so 0.5 M NaCl is 2.922 % w/v and 2 M is 11.688 % w/v.
Molarity of common stock solutions
| Stock solution | Density (g/mL) | Grams of solute per liter | Molarity |
|---|---|---|---|
| Hydrochloric acid 37% w/w | 1.19 | 440.3 | 12.076 M |
| Sulfuric acid 96% w/w | 1.84 | 1766.4 | 18.010 M |
| Glacial acetic acid 99.5% w/w | 1.05 | 1044.8 | 17.398 M |
| Aqueous ammonia 28% w/w | 0.90 | 252.0 | 14.797 M |
| Ethanol 70% v/v | 0.789 (pure ethanol) | 552.3 | 11.988 M |
The calculator’s Common stock solutions presets. Densities are nominal values from Pearson (HCl, ethanol) and the University of Calgary chemistry textbook table (sulfuric acid 18.0 M, acetic acid 17.4 M, ammonia 14.8 M). A bottle’s label or certificate of analysis gives the real figure.
How to use this tool
- Choose M → % to turn a molarity into a percentage, or % → M for the reverse.
- Choose % w/v (grams per 100 mL of solution), % w/w (grams per 100 g of solution) or % v/v (mL of solute per 100 mL), or pick a stock solution to fill everything at once.
- Enter the concentration and the molar mass, or pick a compound from Common Compounds to fill the molar mass.
- For % w/w, enter the density of the solution in g/mL; for % v/v, the density of the pure solute. Read the result, the grams per liter and the two calculation steps.
Frequently asked questions
- How do I convert molarity to percent?
- Multiply molarity by the molar mass to get grams per liter, then divide by 10 to get grams per 100 mL, which is % w/v. For 1.0 M NaCl: 1.0 × 58.44 = 58.44 g/L, and 58.44 ÷ 10 = 5.844 % w/v.
- How do I convert percent to molarity?
- M = % w/v × 10 ÷ molar mass. For % w/w, multiply by the solution density too: M = % w/w × 10 × density ÷ molar mass.
- What is the difference between % w/v and % w/w?
- % w/v is grams of solute per 100 mL of solution. % w/w is grams of solute per 100 g of solution. The two match only when the solution weighs 1 g per mL.
- When does density matter?
- Only for % w/w, and mostly for concentrated solutions. Dilute water-based solutions are close to 1.00 g/mL, so the two percentages nearly agree. Concentrated hydrochloric acid is 37 % w/w with a density near 1.18 g/mL, which gives 37 × 10 × 1.18 ÷ 36.46 = 11.975 M.
- Which density do I enter?
- For % w/w, the density of the finished solution in g/mL, not of the pure solute or of water; the field is preset to 1.0. For % v/v, the density of the pure solute, 0.789 g/mL for ethanol. In % w/v mode the density is ignored and may be left empty.
- How do I convert % v/v to molarity?
- M = % v/v × 10 × density of the pure solute ÷ molar mass. 70 % v/v ethanol is 70 mL of ethanol per 100 mL, so 700 mL per liter, which weighs 700 × 0.789 = 552.3 g; 552.3 ÷ 46.07 g/mol = 11.988 M. The solute volume is taken as measured before mixing, so the figure is close rather than exact for ethanol and water.
Related Tools
View all toolsMolar Mass Calculator
Molar mass of a chemical formula in g/mol from IUPAC atomic weights, with each element’s mass percent. Reads brackets and hydrates such as CuSO4·5H2O.
Molarity Dilution Calculator
Solve C1V1 = C2V2 for any one of the four values: stock or final concentration in M, mM, µM or nM, or stock or final volume in L, mL or µL.
Specific Gravity to Brix Converter
Convert specific gravity to °Brix and °Plato, or Brix to SG, from 1.000 to 1.17874 SG (0 to 40 Brix), with hydrometer temperature correction and ABV.
ABV Calculator
Alcohol by volume (ABV) from original and final gravity, by (OG − FG) × 131.25 or an alternate formula, with attenuation and estimated calories.
Fertilizer N-P-K Mixer
Blend up to three fertilizers and filler to a target N-P-K: 10-10-10 from urea, triple superphosphate and potash is 21.7%, 21.7%, 16.7% + filler.
Water Hardness Converter
Convert water hardness between grains per gallon (gpg), mg/L or ppm as CaCO3, mmol/L and German, French and Clark degrees, and see how hard it is.