Titration Molarity Calculator

Reviewed by the CalculatorHub team, edited by James Graham. Standard acid-base titration equation. Last verified 15 June 2026.

Titration is a precise analytical technique for determining the molarity of an unknown solution. At the equivalence point, the formula Ma * Va * na = Mb * Vb * nb applies, where Ma and Mb are the molarities of acid and base, Va and Vb are their volumes at the equivalence point, and na and nb are the number of acidic or basic equivalents per molecule. Solve for the unknown molarity by rearranging this equation. Enter the known molarity, both volumes, and both n values to find the unknown molarity.

Known molarity Ma (mol/L, acid or titrant)

Volume Va at equivalence point (mL)

na: equivalents per formula unit (acid, e.g., 1 for HCl, 2 for H2SO4)

Volume Vb of unknown (mL)

nb: equivalents per formula unit (base, e.g., 1 for NaOH, 2 for Ca(OH)2)

Unknown molarity Mb (mol/L)

0.00

Titration formula

Ma * Va * na = Mb * Vb * nb Mb = (Ma * Va * na) / (Vb * nb)

Ma = known molarity, Va = volume of titrant used, na = equivalents per acid formula unit, Vb = volume of analyte, nb = equivalents per base formula unit. Volumes must be in the same units (both mL or both L).

Worked example

Titrate 20.00 mL of NaOH with 0.100 M HCl. At equivalence point, 25.00 mL HCl was used.
na = 1 (HCl), nb = 1 (NaOH).
Mb = (0.100 * 25.00 * 1) / (20.00 * 1) = 2.500 / 20.00 = 0.125 mol/L.
The NaOH solution is 0.125 M.

Frequently asked questions

What is a titration?

A titration is a technique in which a solution of known concentration (titrant) is added to a solution of unknown concentration (analyte) until the reaction is complete (equivalence point). The volume of titrant used lets you calculate the unknown concentration.

What is the titration equation Ma*Va*na = Mb*Vb*nb?

At the equivalence point, the moles of equivalents of acid equal the moles of equivalents of base: Ma * Va * na = Mb * Vb * nb. Ma and Mb are molarities, Va and Vb are volumes, and na and nb are the number of H+ or OH- ions provided per formula unit.

What are n values for common acids and bases?

HCl (na = 1), H2SO4 (na = 2), H3PO4 (na = 3), NaOH (nb = 1), Ca(OH)2 (nb = 2), Al(OH)3 (nb = 3). For a strong acid-strong base titration, n is 1 for HCl and NaOH, so the equation simplifies to Ma*Va = Mb*Vb.

What is the equivalence point?

The equivalence point is when the moles of acid exactly equal the moles of base (adjusted for their stoichiometry). An indicator changes color near this point, or it can be identified with a pH meter as the inflection point of the titration curve.

How precise should my volume measurements be?

For accurate molarity calculations, volumes should be measured with a burette (readable to 0.01 mL) or a calibrated pipette. Titration molarity accuracy is limited by volume measurement precision, typically 0.1% for well-executed titrations.

Official sources

IUPAC Gold Book: Titration definition.
NIST: NIST Weights and Measures.

Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.