Xcalcs is an online structural engineering calculation for direct usage into the web. Calculation sheets are user-friendly and intuitive to use.
How does it work?
Users may view the sheets freely and calculate one at a time, so be careful as others might change the same sheet at the same time. But you can use the private sheets through signing up for you to be able to make a copy of the sheet and modify.
There are a lot of sheets in the library for you to view and recalculate. Visit https://www.xcalcs.com/ to learn more.