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pKa and Ka Converter

Convert between Ka and pKa.

Inputs

Results

Ka1.7378 × 10⁻⁵
Acid strengthWeak

Chart

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How to use the pka and ka calculator

Convert between Ka and pKa. Enter pka in the field above; the ka, acid strength are computed instantly and plotted on the chart so you can see how the answer changes.

Common searches this calculator answers include “acid strength”, “pka to ka”, “dissociation constant”, “calculate pka and ka”, “find ka”.

Formula

Ka = 10^(-pKa)
Acid strength = pKa<0?"Very strong":(pKa<4?"Moderately strong":(pKa<10?"Weak":"Very weak"))

Variables

  • pKa — pKa

Worked example

With pka = 4.76, the calculator gives ka ≈ 1.7378 × 10⁻⁵; acid strength ≈ Weak.

Frequently asked questions

What is the pka and ka calculator used for?

Convert between Ka and pKa. It helps with questions such as “acid strength”, “pka to ka”, “dissociation constant”.

What is the formula for the pka and ka calculation?

Ka = 10^(-pKa). Acid strength = pKa<0?"Very strong":(pKa<4?"Moderately strong":(pKa<10?"Weak":"Very weak")). Here pKa is pka.

What inputs do I need for the pka and ka converter calculator?

You need pka. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.

How do I use the pka and ka calculator?

Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.

Is the pka and ka result exact?

Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.

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