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pH & pOH Calculator

Calculate pH, pOH, [H+], [OH-]

Properties

Affects Kw

Results

Enter any one value above to calculate all pH, pOH, [H+], and [OH-]

About pH, pOH, and the Ion Product of Water

pH and pOH are measures of the acidity and basicity of a solution. They are related to the concentrations of hydrogen ions ([H+]) and hydroxide ions ([OH-]) and the ion product of water (Kw).

Key Formulas:

  • pH = -log₁₀[H+]
  • pOH = -log₁₀[OH-]
  • pH + pOH = pKw
  • [H+][OH-] = Kw

Units:

  • Concentration: mol/L (M), mM, μM, nM

Applications:

  • Acid-base chemistry
  • Biological and environmental systems
  • Industrial and laboratory processes