pH Calculator

Convert between pH, pOH and hydrogen or hydroxide ion concentration, with the acid/base verdict.

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Result

3.5

Each whole pH step is a tenfold change in hydrogen ion concentration.

Convert between pH, pOH and hydrogen or hydroxide ion concentration, with the acid/base verdict.

Also known as: poh calculator, hydrogen ion concentration, acid base calculator, ph from molarity, ph to concentration.

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pH = −log₁₀[H⁺] · pH + pOH = 14 at 25 °C

Using the values pre-filled in the calculator above:

the calculator returns:

It is neutral at 25 °C — the hydrogen and hydroxide concentrations are equal at 10⁻⁷ mol/L.

Yes. Very concentrated strong acids above 1 mol/L give negative pH values.