What this calculator does
pH is a logarithmic measure of hydrogen ion concentration. This calculator converts between pH and hydrogen ion concentration for simple chemistry checks.
Formula used
pH equals negative log base 10 of hydrogen ion concentration. Hydrogen ion concentration equals 10 to the power of negative pH.
How to read the result
Because pH is logarithmic, a change of one pH unit is a tenfold change in hydrogen ion concentration.
Assumptions
- Uses ideal concentration values.
- Does not account for activity coefficients.
- Best suited to educational calculations.
Sources and checks
This calculator uses a standard public formula. Where rules or thresholds can change, source links are listed on the relevant page.
Frequently asked questions
Why is pH 7 neutral?
At 25 C, pure water has hydrogen ion concentration around 1 times 10 to the power of negative 7 mol/L, which gives pH 7.