pH Calculator
Convert between pH, pOH, H+ and OH- concentration.
How it works
pH = −log₁₀[H⁺] and pH + pOH = 14 at 25 °C. A concentration of 0.001 mol/L H⁺ gives pH 3. Each pH step is a tenfold change in acidity. Results assume a dilute water solution at 25 °C.
FAQ
Is this calculator free?
Yes. No signup is needed and nothing you enter is stored.
Is the result exact?
Results are rounded for display. For financial, medical, or legal decisions, confirm with a professional.
Do my numbers leave my device?
No. The calculation runs in your browser.