basic

Henderson-Hasselbalch Calculator

pH of a buffer from pKa and concentration ratio.

Estimate the pH of a buffer solution from the pKa of the weak acid and the molar ratio of conjugate base to acid.

Daniel Oh By Daniel Oh
Reviewed by Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

pH = pKa + log₁₀([A⁻] / [HA])

In depth

Estimate the pH of a buffer solution from the pKa of the weak acid and the molar ratio of conjugate base to acid.