Your house, worked out.
Free home-energy calculators that show their method and sources. No sign-up, no phone number. The first one is live: the dew point, for damp windows and wall corners.
Heat load · plannedU-value · plannedSolar yield · plannedBalcony solar · planned
Example house from 1978. More parts of the house become calculators as they are built.
How we calculate
Every result names its formula, its source and its date.
NeutralWe sell nothing and pass on no enquiries. No sign-up, no phone number.
Worked in your browserThe dew point is calculated on your device; what you type is not sent to us.
Method shownMagnus formula with the coefficients of the World Meteorological Organization (WMO-No. 8, 2023, Annex 4.B), valid from −45 °C to +60 °C.
CheckedOur test file checks the result against the definition (saturation at the dew point equals the vapour pressure of the air) and against a second formula.
Questions
Are the calculators free?
Yes. They are free and need no sign-up. The site may show ads later; they will sit below a result, never above it.
Do I have to give my name or phone number?
No. We ask for no contact details and pass on no enquiries.
Is there a German version?
Yes, German calculators are being prepared at /de/; the dew point calculator in English works for every country, in °C or °F.