Normality Calculator
Convert between normality (N) and molarity using the equivalence factor, or find normality directly from gram-equivalents and volume.
Quick answer: Normality (N) = molarity (M) × equivalence factor (n), where n is the number of reactive units (H⁺, OH⁻ or electrons) per formula unit. So 0.5 M H₂SO₄ (n = 2) is 0.5 × 2 = 1.0 N.
Normality expresses concentration in gram-equivalents of solute per litre of solution. It's used in titrations and acid–base and redox work, where the reactive capacity — protons, hydroxides or electrons per molecule — matters more than the raw mole count. Normality is molarity scaled by that equivalence factor.
The formulas
Normality (N) = molarity (M) × n
Normality (N) = gram-equivalents ÷ litres of solution
n = reactive units per formula unit (H⁺, OH⁻ or e⁻)
Normality (N) = gram-equivalents ÷ litres of solution
n = reactive units per formula unit (H⁺, OH⁻ or e⁻)
Worked example
What is the normality of 0.25 M phosphoric acid (H₃PO₄) fully neutralised? It donates 3 protons, so n = 3. N = 0.25 × 3 = 0.75 N.
Frequently asked questions
How do I calculate normality?
Multiply molarity by the equivalence factor n (reactive units per molecule), or divide gram-equivalents by litres.
What is the equivalence factor?
The number of reacting units per formula unit — protons for acids, hydroxides for bases, electrons for redox.
Is normality always bigger than molarity?
When n is greater than 1, yes. For n = 1 (like HCl or NaOH) normality equals molarity.
When should I use normality instead of molarity?
In titrations and acid–base or redox calculations where reactive capacity, not mole count, drives the stoichiometry.
Related calculators
For general and educational use. The equivalence factor depends on the specific reaction.