pH calculator

pH = −log10[H⁺]. Enter any one of pH, pOH, [H⁺] or [OH⁻] — the other three are computed. At 25°C, pH + pOH = 14.

pH
7.00
Neutral
pOH
7.00
[H⁺] mol/L
1e-7
[OH⁻] mol/L
1e-7

Reference

  • pH = −log10[H⁺]
  • pOH = −log10[OH⁻]
  • pH + pOH = 14 (at 25 °C; Kw = 10⁻¹⁴)
  • [H⁺] × [OH⁻] = 10⁻¹⁴

pH < 7: acidic. pH = 7: neutral. pH > 7: basic / alkaline.