Concentration - Molar Converter
Convert molar concentration, the amount of substance per volume, between mol/L, mmol/L, mol/m³, kmol/m³ and other mole-per-volume units. Pick a source and a target unit, enter a value and read the result instantly.
Select two units to see the conversion factor.
Molar concentration is moles per volume. Changing it to grams per liter needs the molar mass of the substance, so this tool only converts between mole-based units.
Molar Concentration Formula
Every molar concentration unit is an amount of substance (mole, millimole or kilomole) divided by a volume (cubic meter, liter, cubic centimeter or cubic millimeter), so each one is a fixed multiple of one reference unit, the mole per cubic meter (mol/m³). To convert, multiply the value by the size of the source unit in mol/m³, then divide by the size of the target unit in mol/m³. The prefixes and volume relationships (1 m³ = 1,000 L = 10⁶ cm³ = 10⁹ mm³) are exact.
What Is Molar Concentration?
Molar concentration, usually called molarity, is the amount of dissolved substance per unit volume of solution. The amount is counted in moles, and one mole contains exactly 6.02214076 × 10²³ particles. The SI unit is the mole per cubic meter (mol/m³), but chemists nearly always use moles per liter (mol/L), written M, because laboratory glassware is measured in liters and milliliters. One mol/L equals 1,000 mol/m³, and one mmol/L equals exactly one mol/m³.
The link between moles and volume is a simple ratio: c = n ÷ V. A solution with 0.5 mol of salt in 2 L has a concentration of 0.25 mol/L. Doubling the amount of substance in the same volume doubles the concentration, while adding solvent to a larger final volume lowers it.
Because it depends on volume, molarity changes slightly with temperature as the liquid expands or contracts. It is different from molality (moles per kilogram of solvent), from mass concentration (grams per liter) and from percent by mass. Only mole-per-volume units are converted here.
Supported Units
This converter supports the following 12 molar concentration units, built from the mole, the millimole and the kilomole divided by the cubic meter, liter, cubic centimeter or cubic millimeter. The last column shows how many mol/m³ one unit equals.
| Unit | Symbol | Value in mol/m³ |
|---|---|---|
| Mole per cubic meter | mol/m³ | 1 |
| Mole per liter | mol/L | 1,000 |
| Mole per cubic centimeter | mol/cm³ | 1,000,000 |
| Mole per cubic millimeter | mol/mm³ | 1,000,000,000 |
| Kilomole per cubic meter | kmol/m³ | 1,000 |
| Kilomole per liter | kmol/L | 1,000,000 |
| Kilomole per cubic centimeter | kmol/cm³ | 1,000,000,000 |
| Kilomole per cubic millimeter | kmol/mm³ | 1e+12 |
| Millimole per cubic meter | mmol/m³ | 0.001 |
| Millimole per liter | mmol/L | 1 |
| Millimole per cubic centimeter | mmol/cm³ | 1,000 |
| Millimole per cubic millimeter | mmol/mm³ | 1,000,000 |
How to Use the Concentration - Molar Converter
- Type the molar concentration in the value box. Decimals and scientific notation such as 0.0025 or 2.5e-3 are accepted.
- Choose the From unit and the To unit.
- The result appears instantly, or press Convert Now. Very large or very small results are shown in scientific notation.
- Use Swap Units to reverse the conversion, Copy Result to copy the answer, open Show this value in all units for a full list, and Clear to start again.
Step-by-step by hand
- Find the size of each unit in the common base unit (mol/m³): 1 mol/L = 1,000 mol/m³ and 1 mol/m³ = 1 mol/m³.
- Divide the source size by the target size to get the conversion factor: 1,000 ÷ 1 = 1,000, so 1 mol/L = 1,000 mol/m³.
- Multiply by your value: 0.5 mol/L × 1,000 = 500 mol/m³.
Concentration cannot be negative, so only zero and positive numbers are accepted.
Common Molar Concentration Conversions
- Laboratory solution: 0.5 mol/L equals 500 mol/m³ and 500 mmol/L.
- Physiological saline: about 154 mmol/L of sodium chloride equals 0.154 mol/L.
- Blood glucose style value: 5.5 mmol/L equals 5.5 mol/m³.
- Industrial streams: 2 kmol/m³ equals 2 mol/L.
- Per cubic centimeter: 0.001 mol/cm³ equals 1 mol/L.
- Dilute environmental sample: 0.02 mmol/L equals 0.02 mol/m³.
- Mass link by hand: sodium chloride has a molar mass of about 58.44 g/mol, so 58.44 g dissolved to make 1 L is 1 mol/L.
Mole per Liter Conversion – Common Values
Quick reference for frequently used values
| Mole/liter (M) | Millimole/liter | Mole/m³ | Kilomole/m³ | Mole/cm³ |
|---|---|---|---|---|
| 0.0001 | 0.1 | 0.1 | 0.0001 | 1e-7 |
| 0.001 | 1 | 1 | 0.001 | 1e-6 |
| 0.01 | 10 | 10 | 0.01 | 1e-5 |
| 0.1 | 100 | 100 | 0.1 | 0.0001 |
| 0.5 | 500 | 500 | 0.5 | 0.0005 |
| 1 | 1,000 | 1,000 | 1 | 0.001 |
| 2 | 2,000 | 2,000 | 2 | 0.002 |
| 5 | 5,000 | 5,000 | 5 | 0.005 |
| 10 | 10,000 | 10,000 | 10 | 0.01 |
Where and Why This Conversion Is Used
- Chemistry and biochemistry labs: stock and working solutions are specified in mol/L, mmol/L or µmol/L.
- Chemical engineering: process equations and reactor models use mol/m³ or kmol/m³, so lab data must be converted.
- Medicine and clinical chemistry: many blood and urine results are reported in mmol/L in SI countries.
- Environmental science: water and soil chemistry uses mmol/L and mol/m³ for ions and nutrients.
- Physical chemistry: rate constants and equilibrium constants depend on the concentration unit used.
- Education: stoichiometry and dilution problems frequently switch between mol/L and mol/m³.
For mass per volume units such as g/L or mg/L use the Concentration - Solution Converter. For moles per time see the Flow - Molar Converter.