pH from pOH Calculator
pH + pOH = 14 at 25°C. Convert one to the other.
Result
pH
10.000
pH + pOH = 14 (at 25°C).
- InputpOH = 4
- OutputpH = 10.000
- [H⁺]1.000e-10 mol/L
- [OH⁻]1.000e-4 mol/L
Step-by-step
- pH = 14 - 4 = 10.000.
How to use this calculator
- Pick conversion direction.
- Enter the value.
- Read the converted result.
About this calculator
In water at 25°C, pH + pOH = 14. This is the auto-ionization product Kw = [H⁺][OH⁻] = 10⁻¹⁴. Take the negative log of both sides and you get the additive form. Use this to switch between pH and pOH whenever convenient.
Frequently asked
At 25°C in water, yes. At other temperatures the constant changes slightly — at 0°C it's ~14.94; at 100°C it's ~12.46.
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