Ion Product of Water Calculator
⚖ Acids, Bases & Equilibrium. Use the Ion product of water formula to find [h⁺], [oh⁻]: pick the value you want, type the others, and the answer updates as you go.
[H⁺]0.001 mol/L
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| [H⁺] | mol/L |
| [OH⁻] | mol/L |
Worked example
Find the [h⁺] when [OH⁻] = 1 × 10⁻¹¹ mol/L.
Using Kw = [H^+][OH^-] = 1.0×10^(-14): [H⁺] = 0.001 mol/L.
Frequently asked questions
What is the formula for Ion product of water?
Kw = [H^+][OH^-] = 1.0×10^(-14).
What do the letters stand for, and what units are used?
[H⁺] in mol/L, [OH⁻] in mol/L.
How do you calculate [h⁺]?
Put the values into Kw = [H^+][OH^-] = 1.0×10^(-14). For example, with [OH⁻] = 1 × 10⁻¹¹ mol/L, [h⁺] = 0.001 mol/L.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value ([h⁺], [oh⁻]) and fill in the others: it rearranges the formula for you.
