pH Calculator

Find pH and pOH from hydrogen ion concentration.

pH 4

pOH 10

Formula: pH = −log₁₀[H⁺] ; pOH = 14 − pH

Step-by-step with your numbers:

1. Values used:

2. [H⁺] concentration = 0.0001 mol/L

4. pH = 4

5. pOH = 10

Did we solve your problem today?

Find the pH of a solution from its hydrogen ion concentration.

The math behind it

pH = −log₁₀ of the [H⁺] concentration. At 25 °C, pH + pOH = 14. Below 7 is acidic, 7 is neutral, above 7 is basic.

[H⁺] = 1 × 10⁻⁴ → pH = 4 (acidic), pOH = 10.

What does each pH step mean?

Each whole pH unit is a 10× change in acidity — pH 4 is ten times more acidic than pH 5.