Acid-base titration curve and pH calculator

How to use (3 steps)

Select the titration type (strong/weak) and enter the concentrations and volumes.
Choose a single-point pH or generate the full titration curve range.
Tap Compute to view pH, regions (buffer/equivalence), and the calculation steps. Copy URL shares the exact setup. The results card below shows the curve and table.

A weak acid + strong base example is preloaded and calculated automatically so you can see results immediately.

Inputs

Titration type

Analyte concentration C_analyte mol/L

Analyte volume V_analyte mL

Titrant concentration C_titrant mol/L

pKa of weak acid

Calculation mode

Single point (pH at a specific added volume) Titration curve (pH vs added volume)

Curve start volume mL

Curve end volume mL

Number of points

Results

How it is calculated

FAQ

What assumptions does this titration calculator make?

It assumes monoprotic strong/weak acids and bases at 25 °C with ideal behaviour. Polyprotic species, activity coefficients, ionic strength, and temperature dependence are out of scope for this tool.

Does the equivalence point always give pH 7?

For strong acid and strong base, the equivalence point is near pH 7 at 25 °C. For weak acid with strong base, the conjugate base is present at equivalence, so the pH will be above 7.

When is the Henderson-Hasselbalch equation valid?

It is a good approximation before the equivalence point while both the acid/base and its conjugate are present. Near or after equivalence, this calculator switches to expressions for the dominant species.

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