Calculates the volume of base solution needed to reach the equivalence point in an acid-base titration.
How it works
At the equivalence point, moles of acid equal moles of base for a 1:1 stoichiometry reaction — this solves that equation for the unknown base volume.
What this does not include
This does not include diluting one solution with solvent — for that different question, use this site’s dilution calculator instead, which uses a visually similar but conceptually different equation.
How to use this calculator
- Enter the acid’s molarity and volume, and the base’s molarity.
A worked example
25 mL of 0.1 M acid neutralized by a 0.2 M base: base volume needed = (0.1 × 25) ÷ 0.2 = 12.5 mL.
10 mL of 0.5 M acid against a 0.25 M base: base volume = 20 mL.
What the variables mean
| Variable | Meaning |
|---|---|
| Acid molarity, acid volume | Concentration and volume of the acid being titrated |
| Base molarity | Concentration of the base solution being added |
Edge cases worth knowing
This assumes a simple 1:1 acid-base reaction stoichiometry. Reactions with different mole ratios (like a diprotic acid) would need the ratio factored in separately, not covered by this basic formula.
A base molarity of zero makes the calculation impossible — a solution with no base concentration can never reach the neutralization point, so the calculator declines to show a result.
Frequently asked questions
What is the “equivalence point” in a titration?
The point where the moles of acid added exactly match the moles of base (or vice versa), fully neutralizing the reaction.
Why does this only cover 1:1 stoichiometry?
Monoprotic acids reacting with monobasic bases neutralize in a simple 1-to-1 mole ratio — polyprotic acids or bases would need an adjusted ratio this calculator doesn’t include.
How is this different from a dilution calculation?
Dilution keeps the same substance and reduces its concentration with solvent; titration involves two different substances (acid and base) reacting until they exactly neutralize each other.
