Humidity calculators
Four tools that turn a hygrometer reading into a decision. Everything runs in your browser — nothing you type is sent anywhere.
The four tools
Dew point
The temperature at which your air starts turning into water. Every condensation problem in your house is decided by this one number.
Dehumidifier size
Square footage and dampness set the capacity. Temperature decides the type — and getting that wrong wastes the whole purchase.
Mold risk
Explains the thing that confuses everyone: why one corner grows mold while the room reads a perfectly healthy 50%.
Should I open the window?
The advice "open a window" is right in winter and wrong on a muggy summer day. This tells you which one today is.
Which one do you need?
If you have a hygrometer reading and want to know whether it is a problem, start on the home page checker — it gives you a ranked plan rather than just a verdict.
If mold keeps returning to one spot while the room reads fine, you need the mold risk calculator. That mismatch is the most misdiagnosed problem in a damp house, and it is a surface temperature issue rather than a room humidity one.
If your windows fog up, the dew point calculator tells you how much margin you have before it happens. And before you open a window to fix any of it, check the outdoor air — in muggy weather that move backfires.