AtticVentCalc is an attic ventilation calculator that works out the net free area and how many ridge, box and soffit vents an attic needs — with no account.
It was built to be fast and private. There are no accounts and no uploads; every calculation happens in your browser. The site may be supported by unobtrusive advertising, which never appears inside the tool itself.
Spotted a bug or want a new feature? Get in touch.