Enter [H⁺], [OH⁻] or a pH value to compute pH, pOH, [H⁺] and [OH⁻], with an acid / neutral / base verdict (pH = −log₁₀[H⁺], pOH = 14 − pH, Kw = 10⁻¹⁴) — 100% in your browser.
Solution--
--
pH
pH = −log₁₀[H⁺]
--
pOH
pOH = 14 − pH
-- mol/L
[H⁺] concentration
Hydrogen-ion concentration
-- mol/L
[OH⁻] concentration
[OH⁻] = Kw / [H⁺]
Formulas: pH = −log₁₀[H⁺], pOH = −log₁₀[OH⁻]. At 25°C, pH + pOH = 14 and Kw = [H⁺][OH⁻] = 1.0 × 10⁻¹⁴. Acidic if pH < 7, neutral if pH = 7, basic if pH > 7. Entering pH back-calculates [H⁺] = 10⁻ᵖᴴ and [OH⁻] = 10⁻ᵖᴼᴴ.
🧪Acid example
A 0.001 M HCl solution. Choose [H⁺] mode, enter 0.001 M → pH = 3.00, pOH = 11.00, [OH⁻] = 1.0 × 10⁻¹¹ mol/L — acidic.
🧼Base example
A 0.0001 M NaOH solution. Choose [OH⁻] mode, enter 0.0001 M → pOH = 4.00, pH = 10.00, [H⁺] = 1.0 × 10⁻¹⁰ mol/L — basic.
Choose what to enter — hydrogen-ion concentration [H⁺], hydroxide-ion concentration [OH⁻], or a pH value — then type the number and click Calculate. Pick the concentration unit (M, mM, µM, nM) when entering [H⁺] or [OH⁻]. The calculator returns pH, pOH, [H⁺] and [OH⁻] in mol/L, plus an acid / neutral / base verdict. pH = −log₁₀[H⁺]; pOH = 14 − pH; Kw = [H⁺][OH⁻] = 10⁻¹⁴ at 25°C.