Titration Calculator

Last updated: June 2026

Use this titration calculator to organise acid–base calculations involving concentration, volume and reacting ratio. It is designed for O-Level, IGCSE, A-Level and Singapore H2 Chemistry students who need to calculate an unknown acid or base concentration from titration data.

Key takeaway: At the equivalence point, the amount of H+ supplied by the acid equals the amount of OH− supplied by the base. The calculation combines n = cV with the number of H+ or OH− supplied per formula unit.
How to use this titration calculator
  1. Choose whether to find the acid concentration, find the base concentration or check the reacting amounts.
  2. Enter the known concentration and both solution volumes.
  3. Select how many H+ the acid supplies and how many OH− the base supplies.
  4. Press Calculate.
  5. Follow the volume conversion, mole calculation and neutralisation steps.

What is a titration?

A titration is an experimental method used to find the concentration of a solution. In a typical acid–base titration, a solution of known concentration reacts with a measured volume of another solution whose concentration is unknown.

The solution in the burette is added gradually to the solution in the conical flask. An indicator or pH probe is used to detect the endpoint.

Acid–base neutralisation

Hydrogen ions from the acid react with hydroxide ions from the base:

H+ + OH− → H2O

The important idea is not that acid volume equals base volume. The reacting amounts depend on concentration and stoichiometry.

The titration formula

The amount of a solution is calculated using:

n = cV

Here, n is amount in mol, c is concentration in mol dm−3, and V is volume in dm3.

Converting titration volume

Titration volumes are normally measured in cm3, but concentration is usually expressed in mol dm−3. Convert using:

volume in dm3 = volume in cm3 / 1000

For example, 25.0 cm3 is 0.0250 dm3.

Using H+ and OH− equivalents

At complete neutralisation:

cacidVacidzacid = cbaseVbasezbase

The symbol z represents the number of acidic H+ ions or hydroxide ions involved per formula unit. For HCl and NaOH, both values are 1. For H2SO4, zacid is 2. For Ca(OH)2, zbase is 2.

Worked examples

HCl and NaOH

Suppose 25.0 cm3 of HCl is neutralised by 20.0 cm3 of 0.100 mol dm−3 NaOH.

c(HCl) = (0.100 × 0.0200 × 1) / (0.0250 × 1) = 0.0800 mol dm−3

H2SO4 and NaOH

Suppose 25.0 cm3 of sulfuric acid is neutralised by 30.0 cm3 of 0.200 mol dm−3 NaOH.

c(H2SO4) = (0.200 × 0.0300 × 1) / (0.0250 × 2) = 0.120 mol dm−3

HCl and Ca(OH)2

Suppose 25.0 cm3 of HCl is neutralised by 20.0 cm3 of 0.150 mol dm−3 Ca(OH)2.

c(HCl) = (0.150 × 0.0200 × 2) / (0.0250 × 1) = 0.240 mol dm−3

Common exam traps

Convert cm3 to dm3. Do not insert a value such as 25.0 directly into n = cV when concentration is in mol dm−3.
Do not assume a 1:1 reacting ratio. H2SO4 can supply two H+, while Ca(OH)2 can supply two OH−.
Endpoint and equivalence point are not identical definitions. The endpoint is the observed indicator colour change, while the equivalence point is the stoichiometric point.
Neutralisation does not always mean pH 7. The calculator checks stoichiometric neutralisation, not the equivalence-point pH of weak-acid or weak-base systems.

Frequently asked questions

What does this titration calculator calculate?

It calculates an unknown acid or base concentration from concentration, volume and stoichiometric information. It can also compare the amounts of H+ and OH− present.

Why must the acid and base factors be included?

One mole of H2SO4 can supply two moles of H+, while one mole of Ca(OH)2 can supply two moles of OH−. These factors determine the correct reacting ratio.

Can the volumes remain in cm3?

When both volumes appear in the same concentration-ratio equation, the common conversion factor cancels. However, the step-by-step solution converts each volume to dm3 so that the mole calculation remains chemically clear.

Does this calculator calculate equivalence-point pH?

No. It handles neutralisation stoichiometry. Use the pH or titration-curve tools when the question asks for pH.

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