What is the difference between molarity and molality?

Molarity (M) is moles of solute per liter of solution and changes with temperature because liquid volume expands. Molality (m) is moles of solute per kilogram of solvent and is temperature-independent, making it preferred for colligative property calculations.

Why do I need to enter molar mass?

Molar mass links mass-based units (mass percent, ppm) to mole-based units (molarity, molality, normality). Without it the converter cannot cross between those two families of units.

What is the n-factor (equivalents per mole)?

The n-factor defines how many equivalents one mole of a substance provides — for example, H2SO4 has n = 2 in acid-base reactions. Normality equals molarity multiplied by n-factor.

Why is solution density required?

Density (g/mL) converts between solution volume (needed for molarity) and solution mass (needed for mass percent). Without density the converter cannot relate volume-based units to mass-based units.

What density should I use for dilute aqueous solutions?

For very dilute aqueous solutions at room temperature, 1.00 g/mL is a good approximation. For concentrated solutions the density can differ significantly — check a reagent datasheet or CRC Handbook.

Does this handle non-aqueous solvents?

Yes. Enter the actual solution density for the solvent system you are using. The converter is solvent-agnostic as long as you provide accurate molar mass and density values.

Solution Concentration Converter

Name: Solution Concentration Converter
Availability: InStock
Author: Nham Vu

Convert solution concentrations between molarity (M), molality (m), normality (N), mass percent (w/w%), volume percent (v/v%), and parts per million (ppm).

Concentration Input

Known Concentration Value

Solute Molar Mass (g/mol)

Solution Density (g/mL)

Equivalents per Mole (n-factor) (for normality, default 1)

Common Solute Molar Masses

Enter a concentration and parameters

Fill in the input fields on the left and click Convert.

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Summary

Convert solution concentrations between molarity (M), molality (m), normality (N), mass percent (w/w%), volume percent (v/v%), and parts per million (ppm).

How it works

Enter the known concentration value and select its unit from the dropdown.
Provide the solute molar mass (g/mol) — required for most conversions.
Provide the solution density (g/mL) — required for molarity and volume-based conversions.
Optionally enter the equivalents per mole (n-factor) to compute normality.
Click Convert to instantly see results in all supported units.
Use the Reset button to clear all fields and start a new conversion.

Use cases

Convert a lab reagent bottle label from mass percent to molarity.
Prepare buffer solutions at a specified molality for temperature-sensitive experiments.
Convert ppm readings from environmental water tests into molar concentrations.
Cross-check normality values when standardizing titration solutions.
Convert between units when following procedures from different regional textbooks.
Verify concentration calculations before mixing hazardous chemicals.
Teach students the relationships between concentration expressions.
Quickly check stock solution concentrations in pharmaceutical compounding.

Frequently Asked Questions

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Dilution Series Calculator Mole Calculator Ph Calculator

Last updated: 2026-05-28 · Reviewed by Nham Vu