basic

pKa ↔ Ka Converter

Convert between Ka and pKa for an acid.

Convert between the acid dissociation constant Ka and its logarithmic form pKa using pKa = −log₁₀(Ka). Pick the direction with a dropdown — Ka → pKa or pKa → Ka.

Dr. Helena Ortiz 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

pKa = −log₁₀(Ka); Ka = 10^(−pKa).

In depth

Convert between the acid dissociation constant Ka and its logarithmic form pKa using pKa = −log₁₀(Ka). Pick the direction with a dropdown — Ka → pKa or pKa → Ka.