Calculator Suite
By Arun Kishore, P.Eng. · Published · Updated
Free, open-source tools for the lookups every structural engineer repeats. Built for myself, left on the web for everyone.
Why build these at all
Every structural engineer keeps a private pile of the same lookups. The density of a given material. Which snow and wind station is closest to a site. How long a bar needs to develop in tension. None of it is hard. All of it is slow, because the answer lives in a code table, a manual appendix, or a spreadsheet you built once and no longer quite trust.
loadings.struct.work is a free set of 14 structural engineering calculators covering NBCC 2020 loads, CSA S16 steel connections and CSA A23.3 concrete design, built in Python and Streamlit. It is that private pile, cleaned up and put on the web: no sign-up, most of it open-source. I built the first few for myself and kept going, because every one I finished was one I never had to redo.
What's in the suite
Loadings
Steel
These calculators are aids, not a substitute for engineering judgment. Check results independently and against the governing code edition before relying on them.
Each tool has its own page with inputs, code clauses and limitations.
The stack
Boring on purpose. Each tool is a Streamlit app in Python, self-hosted on a server I manage behind the struct.work domain. Streamlit because the point was to ship the calculation, not to hand-build a form and a results table for the fortieth time. Self-hosted because I wanted to own the whole path from code to URL, and because running my own infrastructure was a skill I wanted anyway.
No database, no accounts, no signup wall. You land on the page, you get the number, you leave.
What running them taught me
The tools people used taught me where my assumptions were wrong.
The interface is the hard part, not the math. The development-length calculation is a page of code. Making it clear which bar, which concrete, which condition, without burying the user in inputs, took longer than the engineering did.
Scope discipline beats ambition. The one-way slab designer is still a proof of concept because slab design has more branches than a clean afternoon can cover, and I would rather leave it honest than ship it half-trusted.
Free and useful travels on its own. I never marketed any of this.
Try them, or buy me a coffee
The suite lives at calc.struct.workopens in a new tab. It is free and most of it is open-source. If one of these saved you an afternoon, you can buy me a coffeeopens in a new tab.