Solution Molarity Calculator
Prepare chemistry solutions from mass, concentration, volume, or percent weight per volume. Choose the calculation you need and enter the known values.
Need only concentration unit conversion (M, mM, µM, nM)? Use the Molarity Unit Converter. Working with proteins by molecular weight in kDa? Use the Protein Molarity Calculator.
What are you calculating?
Mass to Molarity
M = mass (g) / molar mass (g/mol) / volume (L)
Use this when you know how much solute was dissolved and the final solution volume.
Molarity
Molarity (M) = moles of solute / liters of solution
Moles = mass in grams divided by molar mass in g/mol.
Moles = mass in grams divided by molar mass in g/mol.
Molarity to Mass
mass = molarity × volume × molar mass
Use this to find how much dry solute to weigh out for a target concentration and final volume.
Mass to weigh
mass (g) = M × L × g/mol
Dissolve the calculated mass, then bring the solution up to the final volume.
Dissolve the calculated mass, then bring the solution up to the final volume.
Molarity to Volume
volume = mass / (molarity × molar mass)
Use this when you have a known mass and want the final volume needed to reach a target molarity.
Final volume
volume (L) = mass (g) / [molarity (M) × molar mass (g/mol)]
This is the final total volume, not the volume of solvent to add.
This is the final total volume, not the volume of solvent to add.
% w/v and Molarity
M = (% w/v × 10) / molar mass
Convert percent weight per volume to molarity, or molarity back to percent weight per volume.
Convert:
Converted concentration
% w/v means grams of solute per 100 mL solution.
Therefore 1% w/v = 10 g/L, and molarity = g/L divided by molar mass.
Therefore 1% w/v = 10 g/L, and molarity = g/L divided by molar mass.
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