Molarity Calculator

In case you were looking for a: Molecular Weight calculator

Enter any three values to calculate the fourth (Mass to Moles / Molarity / Volume).

Mass (g): (grams)

Molecular Weight (g/mol): (grams per mole)

Volume (L): (liters)

Concentration (mol/L or M): (moles per liter or Molarity)

Result:

Understanding Molarity and Calculations

Molarity ($M$) is a measure of the concentration of a solute in a solution, or of any chemical species, in terms of amount of substance in a given volume of solution. It is defined as the number of moles of solute per liter of solution.

The fundamental formula for molarity is:

$$ M = \frac{\text{moles of solute}}{\text{liters of solution}} $$

From this, we can derive other useful relationships:

Moles (mol): $ \text{Moles} = \frac{\text{Mass (g)}}{\text{Molecular Weight (g/mol)}} $
Molarity (M): $ M = \frac{\text{Moles}}{\text{Volume (L)}} $
Mass (g): $ \text{Mass} = \text{Molarity (M)} \times \text{Volume (L)} \times \text{Molecular Weight (g/mol)} $
Volume (L): $ \text{Volume} = \frac{\text{Moles}}{\text{Molarity (M)}} $
Molecular Weight (g/mol): $ \text{Molecular Weight} = \frac{\text{Mass (g)}}{\text{Moles}} $

How to Use This Tool:

This calculator is designed to be flexible. Simply input any three of the four values (Mass, Molecular Weight, Volume, Concentration), and the tool will automatically calculate the missing fourth value. For example:

To find the **Mass** needed to prepare a solution: Enter Molecular Weight, Volume, and Concentration.
To find the **Molarity** of a solution: Enter Mass, Molecular Weight, and Volume.
To find the **Volume** needed for a specific amount: Enter Mass, Molecular Weight, and Concentration.
To find the **Molecular Weight** of a substance given its solution properties: Enter Mass, Volume, and Concentration.

Ensure your units are consistent with those specified (grams for mass, grams/mole for molecular weight, liters for volume, and moles/liter for concentration).

Important Considerations:

Significant Figures: Always consider the significant figures of your input values when interpreting the calculated result.
Temperature: Molarity is slightly temperature-dependent because volume can change with temperature. However, for most general lab purposes, this effect is negligible.
Solute State: This calculator assumes the solute is fully dissolved and does not account for phenomena like precipitation or gas solubility.