pH Calculator
Calculate pH from hydrogen ion concentration or find H+ concentration from pH.
Shows whether a solution is acidic, basic, or neutral.
pH Result
pH measures how acidic or basic a solution is on a scale of 0 to 14.
pH = -log₁₀([H⁺])
[H⁺] = 10^(-pH)
pH Scale:
- 0–6.9: Acidic (more H⁺ ions)
- 7.0: Neutral (pure water)
- 7.1–14: Basic/Alkaline (fewer H⁺ ions)
Common pH values:
- Battery acid: ~1
- Lemon juice: ~2
- Coffee: ~5
- Pure water: 7
- Baking soda: ~9
- Bleach: ~13
Each whole pH number represents a 10× change in H⁺ concentration. pH 4 is 10 times more acidic than pH 5.