pH Calculator
Calculate pH from hydrogen ion concentration
How to Use
- Select what you want to calculate from (H⁺ concentration, OH⁻ concentration, pH, or pOH)
- Enter the known value in the input field
- Click calculate to get all related values
- View pH, pOH, ion concentrations, and acid/base classification
- Copy the results to your clipboard for later use
About This Tool
Our free pH calculator helps you calculate pH from hydrogen ion concentration or vice versa. Using the fundamental chemistry formula pH = -log₁₀[H⁺], you can convert between pH and ion concentrations instantly. The calculator also calculates pOH and shows the acid/base classification (strongly acidic, weakly acidic, neutral, weakly basic, strongly basic). Perfect for students, chemists, and anyone working with acid-base chemistry. The calculator supports scientific notation for very small concentrations and automatically calculates the complementary values (pH ↔ pOH, [H⁺] ↔ [OH⁻]). All calculations happen instantly in your browser with complete privacy.
Frequently Asked Questions
What is the pH formula?
The pH formula is pH = -log₁₀[H⁺], where [H⁺] is the hydrogen ion concentration in moles per liter (M). pH measures how acidic or basic a solution is on a scale from 0 to 14.
What is the pH scale?
The pH scale ranges from 0 to 14. A pH of 7 is neutral, below 7 is acidic (lower is more acidic), and above 7 is basic (higher is more basic). Each unit represents a tenfold change in acidity.
What is the relationship between pH and pOH?
pH and pOH are related by the equation pH + pOH = 14 at 25°C. pOH measures the hydroxide ion concentration [OH⁻] using pOH = -log₁₀[OH⁻].
Can I calculate ion concentration from pH?
Yes, you can calculate hydrogen ion concentration from pH using [H⁺] = 10^(-pH). The calculator also calculates the complementary [OH⁻] concentration automatically.
