Old guy (80) lots of time no money!

So I build stuff. I used to build with wood and metal. I used to build with transistors and electronics.

Now I build with a computer.

This site offers some Freebies and some paid scripts.  There is a collection of calculators you can download for your mobile device or desktop for various trades such as builders, electricians, plumbers, HVAC, surveyors and midical clinicians.

All are offered as-is with no warranty and are intended to be educational in nature. While all effort was made to assure accuracy, if in doubt always check against a known authority.  These are not intended to serve in an official capacity with regards to an regulatory compliance.  As with all such things, use at your own risk. I assume no liability for errors.