pH Calculator
Calculate pH, pOH and ion concentration.
About this tool
pH measures how acidic or basic a solution is, based on the concentration of hydrogen ions. Enter either the hydrogen ion concentration or a pH value directly, and get pH, pOH, and both ion concentrations.
Key Features
- Calculate from [H+] concentration or pH directly
- Also gives pOH and [OH-]
- Covers the full 0–14 pH range
How to Use
- Choose whether you're entering [H+] concentration or a pH value.
- Enter the value.
- Click Calculate.
Benefits
- Check chemistry homework on acid-base equilibrium
- Convert between ion concentration and pH
- Understand where a solution falls on the acid/base scale
Frequently Asked Questions
Below 7 is acidic, exactly 7 is neutral (pure water at 25\u00b0C), and above 7 is basic (alkaline). The scale runs from 0 to 14 for most common aqueous solutions.
In water at 25\u00b0C, pH + pOH always equals 14 \u2014 so a solution's pOH can always be found by subtracting its pH from 14, and vice versa.