Normality [local] (N) is a concentration unit that is particularly useful in carrying out calculations resulting from titrations. Normality is defined as the number of equivalents per liter of solution.

Equivalents (Eq) is equal to the mass divided by the equivalent mass. There always is a simple relationship between moles and equivalents. In nearly all cases, the number of equivalents is equal to the number of moles multiplied by a small whole number: 1, 2, 3, etc.

For an acid, the equivalent mass is the molar mass (MM) divided by the number of ionizable H⁺ ions. For a base, it is the molar mass divided by the number of ionizable OH^- ions. For example, H₂SO₄ has 2 ionizable H⁺ ions, and an equivalent mass of 98g/mole/2 or 49g/Eq.

Molarity can be converted to normality by multiplying the molarity by the number of available acid or base moieties per molecule. (Normality is always equal to or larger than molarity by some whole number multiple.)