pH / Acid–Base Calculator
Enter any one value (concentration or pH/pOH) — the other three update automatically.
Inputs
Neutral
pH = 7.00, pure water at 25°C
01234
56789
1011121314
AcidicNeutralBasic
At 25°C, water self-ionises so that
Kw = [H+][OH−] = 1.0×10−14,
giving pKw = pH + pOH = 14. pH below 7 is acidic, above 7 is basic, exactly 7 is neutral.