pH Calculator

Enter pH, pOH, [H+] or [OH-] and get the others plus acidic, neutral or basic.

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Enter any one value; the others are derived from it.

pOH

[H+]

[OH-]

About this tool

Enter any one of pH, pOH, [H+] or [OH-] and the rest are computed live in your browser using pH = -log10[H+], pH + pOH = 14 and [H+][OH-] = 1e-14.

Which value should I enter?

Just one — type a pH, pOH, hydrogen-ion or hydroxide-ion concentration and the other three fields and the result update automatically.

How is acidic versus basic decided?

A pH below 7 is acidic, exactly 7 is neutral and above 7 is basic, based on the standard scale at 25 °C where the ion product of water is 1×10⁻¹⁴.