pH Calculator

Live, synced inputs • PDF export • Step-by-step derivation

🧭 Mode (help)

⚗️ Concentration of an acid

🧪 Concentration of a base

⚖️ Mass & volume of an acid

🧴 Mass & volume of a base

💧 [H⁺], [OH⁻], or pOH

Inputs

🧪 Acid (?)

📦 Concentration (?)

Ion panel (always editable)

🧫 [H⁺] (?)

🧫 [OH⁻] (?)

📉 pOH (?)

Result

🧪 pH

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🧫 [H⁺] (M)

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Related numbers

Step-by-step derivation

Choose a mode and start typing—your algebra will appear here with numbers plugged in.

References & notes

Topic	Note
pH definition	pH = −log10([H⁺]), where [H⁺] is in mol·L⁻¹.
pOH relation	pH + pOH = 14 assumed at 25 °C (Kw = 1.0×10⁻¹⁴).
Weak acid/base	Exact quadratic: K = x²/(c − x) ⇒ x = (−K + √(K² + 4Kc))/2.
Strong species	Full dissociation: [H⁺] ≈ n_H·c, [OH⁻] ≈ n_OH·c.