dilutioncalculator.co.uk§ Verified 20 Jun 2026 · Reviewed by A. Hargreaves, MChem (Hons)

Molarity dilution calculator

Molarity is moles of solute per litre of solution. Use C₁V₁=C₂V₂ to dilute a stock to a working concentration.

§ MeasureDesk
Concentrate
76.9 ml
Water
4 923.1 ml
Total at strength
5 000 ml
1.54 % v/v
§ PourScale · true-to-ratio
concentrate 1.54 %water 98.46 %

§ 1Worked example

  1. Stock = 1 M NaCl. Target = 0.15 M (physiological saline). Volume = 500 ml.
  2. V₁ = (0.15 × 500) ÷ 1 = 75 ml of stock.
  3. Add 75 ml of stock to a 500 ml volumetric flask. Top up with water to 500 ml.

§ 2Hydrates and waters of crystallisation

CuSO₄·5H₂O formula mass is 249.7 g/mol. Weighing 25 g into 100 ml gives a 1 M Cu²⁺ solution. For the anhydrous salt (159.6 g/mol), 16 g would give the same molarity. Many SDS quote the hydrate by default.[7]

§ 3Related