pH Calculator

Calculate pH, [H⁺], [OH⁻], and pOH at 25°C (Kw = 1.0 × 10⁻¹⁴)

pH
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[H⁺]
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pOH
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[OH⁻]
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Enter a value to see the pH zone
pH = -log[H⁺]   |   [H⁺] = 10⁻ᵖᴴ   |   pOH = 14 - pH   |   Kw = [H⁺][OH⁻] = 10⁻¹⁴
Kw = 1.0 × 10⁻¹⁴ at 25°C
In pure water: [H⁺] = [OH⁻] = 1.0 × 10⁻⁷ M, giving pH = 7 (neutral)