Method
Molarity M = moles of solute ÷ litres of final solution; dilution uses M₁V₁=M₂V₂ under additive ideal assumptions.
Everyday worksheet
Molarity and Dilution Calculator
Calculate solution molarity from moles and final volume, then inspect amount concentration and a target-dilution volume.
The calculation runs locally. Results include the intermediate values, unit conversions and assumptions needed to audit the answer.
Method, assumptions and practical use
How the Molarity and Dilution Calculator works
Molarity M = moles of solute ÷ litres of final solution; dilution uses M₁V₁=M₂V₂ under additive ideal assumptions. Inputs stay in this browser, and the result table exposes conversions and assumptions for independent checking.
Interpret the result
Molarity is amount per final solution volume, not solvent volume before mixing.
Check the assumptions
Laboratory preparation requires compatible chemistry, calibrated volumetric equipment and appropriate safety procedures.
Local calculation
Everything runs in this browser. Inputs are not sent to an external calculator.
Rounding
Displayed values may be rounded for readability while calculations use full floating-point precision unless the tool explicitly uses exact integers.
Scope
Laboratory preparation requires compatible chemistry, calibrated volumetric equipment and appropriate safety procedures.
How to calculate solution molarity
Molarity is moles of solute divided by the final solution volume in litres: M = n ÷ V. If you start with mass in grams, first divide by the compound's molar mass in grams per mole to find moles. For example, 0.5 mol in 2 L is 0.25 mol/L.
How does dilution work?
When adding solvent without changing the amount of solute, the ideal relationship is M₁V₁ = M₂V₂. Use the same volume units on both sides. This assumes no reaction or loss of solute; check laboratory protocols for precise preparation.
Plan with context
Molarity connects amount of solute with final solution volume.
Correct results depend on using litres for final solution volume, distinguishing mass from moles, and keeping dilution units consistent on both sides of the equation.
Use final solution volume
Molarity uses the final volume of the completed solution, not simply the amount of solvent poured before the solute was added.
Convert mass to moles
When mass is given, divide it by the compound's molar mass before applying M = n/V. Preserve enough significant figures through the calculation.
Keep volume units consistent
Convert millilitres to litres for M = n/V. In M1V1 = M2V2, matching volume units cancel as long as both sides use the same unit.
Dilution conserves solute
The ideal dilution equation assumes the number of moles of solute remains constant while additional solvent changes the concentration and total volume.
Show the rearranged formula
Solving for moles, volume, initial concentration, or final concentration uses the same relationship rearranged around the unknown variable.
Laboratory conditions matter
Temperature, non-additive volumes, purity, hydration state, reactions, and measurement uncertainty can make real preparation differ from an ideal calculation.
Included
Molarity, moles, litres and millilitres, formula rearrangement, molar-mass context, ideal dilution, unit conversions, and worked calculation logic.
Not included
Activity coefficients, ionic strength, density-based preparation, reaction stoichiometry, purity correction, uncertainty propagation, or laboratory safety instructions.
Use it well
Write down the known values and units, convert before substituting, use the final solution volume, and prepare laboratory solutions using an approved procedure and calibrated glassware.