Water Autoionization Kw Calculator
Estimate the ion product of water Kw, pH and pOH of pure water at a given temperature.
Compare Your Options And Get Clear Answers
Estimate the ion product of water Kw, pH and pOH of pure water at a given temperature.
Water Autoionization Kw Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Enter Values
Fill in each field with your own numbers.
Calculate
Results update as you change the inputs.
Review
Read the breakdown and the explanation.
Adjust
Change values to compare scenarios.
Water Quick Guide
Typical values for reference.
| Temp C | pKw | pH | Kw |
|---|---|---|---|
| 0 °C | 14.941 | 7.470 | 1.15e-15 |
| 25 °C | 13.995 | 6.997 | 1.01e-14 |
| 50 °C | 13.261 | 6.631 | 5.48e-14 |
| 100 °C | 12.260 | 6.130 | 5.49e-13 |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Water Autoionization Kw Calculator FAQ
Answers to common questions about this calculator.
The ion product of water, [H+][OH-], equal to 1.0 x 10^-14 at 25 C.
Its pH falls below 7, but it stays neutral because [H+] equals [OH-].
pKw = 4470.99 / T – 6.0875 + 0.01706 T; Kw = 10^-pKw.
It is an estimate based on the inputs you enter. Check real quotes, labels or official guidance for important decisions.