💧 Karl Fischer Water Content Calculator
Calculate water content and percent water (w/w) from volumetric Karl Fischer titration results.
Frequently asked questions
What is the KF titer (factor)?
The titer, or factor, expresses how many milligrams of water are neutralized by 1 mL of Karl Fischer titrant. It's determined experimentally by titrating a certified water standard of known water content and calculating the titrant's actual strength, since commercial titrants can vary slightly from their nominal labeled value.
Why does the titer need to be re-standardized regularly?
Karl Fischer titrant reagents (both one-component and two-component systems) degrade over time and are sensitive to atmospheric moisture ingress, which changes their effective strength. Regular re-standardization against a certified water standard ensures the titer used in calculations reflects the titrant's actual current strength.
Does this work for both volumetric and coulometric KF titration?
This calculator applies to volumetric Karl Fischer titration, where titrant volume and titer are used directly. Coulometric KF titration measures water mass directly via Faraday's law (based on charge passed) rather than titrant volume, and uses a different calculation not covered by this tool.
Accuracy & how this is derived
Derivation: Standard volumetric Karl Fischer calculation: water mass equals titrant volume multiplied by the titer (mg water per mL titrant), then expressed as a percentage of sample weight.
Validated against: Standard volumetric Karl Fischer titration calculation described in USP General Chapter <921> Water Determination and ASTM E203.
⚠️ For educational and research support only — verify critical results independently before use in regulated, clinical, or publication-bound work.
✔ Last updated: July 2026 · Report an error
Calculating water content by Karl Fischer titration
Karl Fischer titration determines water content by reacting a sample with a titrant that consumes water in a stoichiometrically defined reaction, so the volume of titrant needed to reach the endpoint directly reflects how much water was present. Multiplying the titrant volume by its standardized titer (milligrams of water neutralized per milliliter) gives the absolute mass of water in the sample, which is then expressed as a percentage of the original sample weight to report water content on a familiar, comparable w/w basis.