Skip to main content

All Calculators & Converters

All calculators

Molarity Calculator

Compute solution molarity M (mol·L⁻¹) from moles n and volume V, or derive n from mass m and molar mass M. See steps, and visualize results with a mini bar chart and a molarity gauge.

Background

By definition, M = n / V with volume in liters. If you don’t have moles, first compute n = m / M using the solute mass m (g) and molar mass M (g·mol⁻¹).

Enter known values

Solute amount:

Provide n directly, or give m and M to compute n = m / M.

Solution volume:

Volume is converted to liters automatically when computing M.

Show:

Step-by-step working

Mini chart: n, V, M

Molarity gauge

Round to sensible significant figures

Quick picks:

Chips prefill fields. We’ll compute and show the visuals.

Result:

No results yet. Enter inputs and click Calculate.

How to use this calculator

If you know moles: enter n and V → M = n / V.
If you know mass: enter m and molar mass M, plus V → n = m / M → M = n / V.
Units: volume is converted to liters; molarity is mol·L⁻¹.

Formula & Equation Used

Molarity: M = n / V

Moles from mass: n = m / M

Example Problems & Step-by-Step Solutions

Example 1 — 5.00 g NaCl in 250 mL

M(NaCl) ≈ 58.44 g·mol⁻¹ → n = 5.00 / 58.44 = 0.0856 mol; V = 0.250 L → M = 0.342 mol·L⁻¹.

Example 2 — 0.100 mol in 100 mL

V = 0.100 L → M = 0.100 / 0.100 = 1.00 mol·L⁻¹.

Example 3 — 18.015 g H₂O in 500 mL

M(H₂O) = 18.015 g·mol⁻¹ → n = 18.015 / 18.015 = 1.000 mol; V = 0.500 L → M = 2.00 mol·L⁻¹.

Frequently Asked Questions

Q: Can I enter volume in mL?

Yes. We convert mL to L automatically.

Q: Do I need moles?

No. You can give mass and molar mass to compute moles first.

Q: What does “Round to sensible significant figures” do?

It reports values to ~3 significant figures (switching to scientific notation for very small/large numbers).

Calculating Molar Mass

2. Atoms & Elements

2. Atoms & Elements

3. Chemical Reactions

6. Chemical Quantities & Aqueous Reactions

6. Chemical Quantities & Aqueous Reactions

Solution Stoichiometry

6. Chemical Quantities & Aqueous Reactions

Parts per Million (ppm)

2. Atoms & Elements - Part 1 of 4

6 topics 14 problems

2. Atoms & Elements - Part 2 of 4

6 topics 14 problems

2. Atoms & Elements - Part 3 of 4

6 topics 14 problems

2. Atoms & Elements - Part 4 of 4

5 topics 14 problems

3. Chemical Reactions - Part 1 of 3

5 topics 13 problems

3. Chemical Reactions - Part 2 of 3

6 topics 13 problems

3. Chemical Reactions - Part 3 of 3

5 topics 13 problems

6. Chemical Quantities & Aqueous Reactions - Part 1 of 3

6 topics 13 problems

6. Chemical Quantities & Aqueous Reactions - Part 2 of 3

6 topics 12 problems

6. Chemical Quantities & Aqueous Reactions - Part 3 of 3

5 topics 12 problems

14. Solutions - Part 1 of 3

4 topics 12 problems

14. Solutions - Part 2 of 3

5 topics 12 problems

14. Solutions - Part 3 of 3

5 topics 12 problems

Calculating Molar Mass

6. Chemical Reactions & Quantities

6. Chemical Reactions & Quantities

6. Chemical Reactions & Quantities

Parts per Million (ppm)

Solution Stoichiometry

6. Chemical Reactions & Quantities - Part 1 of 2

6 topics 9 problems

6. Chemical Reactions & Quantities - Part 2 of 2

3 topics 8 problems

9. Solutions - Part 1 of 3

5 topics 12 problems

9. Solutions - Part 2 of 3

7 topics 11 problems

9. Solutions - Part 3 of 3

7 topics 11 problems

Calculating Molar Mass

5. Molecules and Compounds

6. Chemical Composition

6. Chemical Composition

Solution Stoichiometry

5. Molecules and Compounds

11 topics 33 problems

6. Chemical Composition

4 topics 12 problems

13. Solutions - Part 1 of 2

12 topics 36 problems

13. Solutions - Part 2 of 2

2 topics 6 problems

Chemical Concentrations

1. Chemical Measurements

1. Chemical Measurements - Part 1 of 2

4 topics 12 problems

1. Chemical Measurements - Part 2 of 2

1 topic 3 problems

Concentration Calculator

Calculate molarity, solute mass, or solution volume — with built-in conversions

Mole Fraction Calculator

Compute mole fractions and partial pressures with steps and chart

Solution Dilution Converter

Easily convert between stock and diluted solutions — fast, visual, and accurate.

Percentage Concentration to Molarity Calculator

Convert any % solution to molarity — fast, clear, and accurate

PPM to Molarity Calculator

Convert solution concentration between ppm and molarity (mol/L)

Molality Calculator

Compute molality (mol/kg) from solute amount and solvent mass

Moles ↔ Particles Calculator

Quickly convert moles and particles using Avogadro’s number

Mass ↔ Moles Calculator

Easily calculate moles, grams, or molar mass in one step

Mole Calculator

Calculate moles from mass, particles, or gas data — instantly

Mass Percent Calculator

Compute % w/w, % w/v, % v/v—solve any missing value fast

Serial Dilution Calculator

Build serial dilution series with clear steps, tables, and visuals

Avogadro’s Number Calculator

Convert particles, moles, and mass with Avogadro’s constant

Percent Solution Converter

Convert w/w, w/v, and v/v percent solutions — with clear steps

Calculate pH, pOH, or ratios for acids and bases

Normality Calculator

Step-by-step normality calculations for acids, bases, salts and more

Dilution Factor Calculator

Find C₁, C₂, V₁, or V₂ — with automatic unit conversions and steps

Molar Mass from Chemical Formula Calculator

Find the molar mass of compounds instantly—just enter the formula

Grams ↔ Moles Converter

Convert grams and moles via molar mass, with steps