Math & Science
pH Calculator
Calculate pH, pOH, and ion concentrations
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Frequently asked questions
What does pH measure?
The acidity or basicity of a solution on a scale of 0-14. 7 is neutral.
Why is scale logarithmic?
Because H⁺ concentrations vary by many orders of magnitude (10⁻¹ to 10⁻¹⁴ M).
Does temperature affect pH?
Yes, pH of neutral water varies with temperature (7.0 at 25°C, 6.14 at 100°C).
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About this tool
This pH Calculator turns your inputs into practical results. Provide Value, Input Type, and pH to calculate pH and pOH.
Adjust values to compare scenarios and see how sensitive the result is. The calculation uses the numbers as entered, so double-check units and expect small differences from rounding in the displayed totals.