pH Calculator

Calculate pH from strong/weak acid or base concentration, or directly from [H+], [OH−], or pOH.

Inputs

Calculation mode

Assumption

Uses pH + pOH = 14 at 25 °C.

Concentration

Unit

Ion equivalents

Guide

For example: HCl = 1, H₂SO₄ = 2, NaOH = 1, Al(OH)₃ = 3.

Ka / Kb

Guide

Enter the dissociation constant for the weak acid or weak base.

pOH

Guide

pH = 14 − pOH at 25 °C.

Results

—

pOH

—

[H+]

—

[OH−]

—

Step-by-step

Choose a mode, enter values, and click Calculate.

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