Chemistry · Concentration
Normality calculator.
Normality from grams, grams for a target normality, or molarity to normality. Set the n-factor for your reaction.
Inputs
Result
Enter your values.
Normality formula
Normality (N) is the number of equivalents of solute per litre of solution. N = M x n, where M is molarity and n is the number of reactive units per mole (H+ for an acid, OH- for a base, electrons for a redox reaction). The equivalent weight = molar mass / n, so grams = N x litres x equivalent weight.
Worked example 1. To make 1 L of 1 N sulfuric acid for an acid-base reaction (n = 2, molar mass 98.072 g/mol): equivalent weight = 98.072 / 2 = 49.036 g/eq, so weigh 49.04 g of pure H2SO4 (a 0.5 M solution). In practice you would dilute a concentrated stock, see the stock dilution calculator.
Worked example 2. 500 mL of 0.1 N NaOH (n = 1, 39.997 g/mol): 0.1 x 0.5 = 0.05 eq, 0.05 x 39.997 = 2.000 g.
The n-factor belongs to the reaction, not just the compound. An oxidant can transfer a different number of electrons in acid than in neutral solution, and an acid may give up one or all of its H+, so the same bottle can have different normalities. That is why IUPAC and NIST discourage the term normality and prefer molarity with the reaction stated.
Frequently asked questions
What is the formula for normality?
Normality = equivalents of solute / litres of solution, which equals molarity x n-factor.
How do I find the equivalent weight?
Divide the molar mass by the n-factor. For H2SO4 in an acid-base reaction, 98.072 / 2 = 49.036 g/eq.
How do I convert molarity to normality?
Multiply molarity by the n-factor. A 0.5 M H2SO4 solution is 1 N for acid-base work.
Why is normality discouraged?
The n-factor depends on the reaction, so one solution can have several normalities. IUPAC and NIST discourage the term and recommend molarity instead.
Sources
Checked
- Wikipedia: Equivalent concentration (normality N = M x f_eq; IUPAC and NIST discourage the term)
- OpenStax Chemistry 2e, 3.3 Molarity
- CIAAW: Abridged Standard Atomic Weights 2024 (molar masses)
Runs entirely in your browser. Nothing you type is sent or stored.
Lab safety and scope
This is arithmetic, not professional advice. Check every result against your own procedure, the safety data sheet (SDS) for each chemical, and your lab supervisor or instructor before you prepare, mix or dispose of anything. Verify values on the reagent bottle, since purity and hydration state change the real molar mass.