For teachers
Maintained by the PhDino author · Written 17 October 2026
PhDino is free to use in a classroom: there is no account to make, and nothing a student types into a calculator is sent anywhere. This page collects what is most useful for teaching, from calculators you can put on your own course page to a weekly problem with a worked answer, and says plainly how far the numbers can be trusted.
The latest Dino Challenge · RSS feed · A calculator page and its formula card · How the numbers are checked · Contact
Example: a calculator with the worksheet’s numbers
This is the code for the Beam Deflection calculator, opening on a 20 ft span under 500 lb/ft:
<iframe src="https://phdino.com/embed.html?calc=beam-deflection&span=20&load=500&modulus=1600&momentOfInertia=178" title="Beam Deflection calculator" width="100%" height="640" style="border:0;max-width:880px" loading="lazy"></iframe> <p style="font:12px sans-serif;margin:4px 0">Calculator by <a href="https://phdino.com/calc/beam-deflection">PhDino</a></p>
Put a calculator on your course page
Every calculator can be embedded. Open it, choose File ▸ Copy embed code, and paste the code into any page that accepts HTML: a course site, a blog, or a learning platform that allows embedded content. The embedded calculator works on its own, with its live diagram, and links back to its full guide.
It can also start with your numbers already filled in, so students see the case from the worksheet. Add the values to the address with the same names a shared result link uses (File ▸ Copy link to this result shows them), as in the example above.
Formula cards
Each calculator page has a numbered formula card: the key formula and its variables on the front, and on the back a worked example run through the calculator itself. "Save as image" downloads both faces with the page address printed on them, ready for a slide or a handout.
A worked problem every week
The Dino Challenge sets one problem a week that a single calculator answers, and publishes the worked answer with the next one. The archive keeps every past problem with its answer, and the RSS feed announces new ones, so they work as ready-made exercises: set the problem, then compare with the published working.
How far to trust the numbers
The text and code were drafted with the help of AI and are maintained by one person. Every calculator is checked by an automated test suite against values worked out independently, and the Methodology page lists what is tested and every error found and corrected so far. No licensed engineer has reviewed the site.
The formulas are teaching-grade: good for learning, exploring and checking homework, not for design. If PhDino and a textbook disagree, please say so through the Contact page; a verified error is fixed and logged.
Using PhDino in class
Embedding the calculators, linking to any page, and showing the pages, diagrams and formula cards in class are all welcome, as long as the PhDino credit stays on them. Republishing the articles or diagrams as your own is not; the Terms of Service have the details. Suggestions for a calculator, a unit or an example that would help a lesson are welcome through the Contact page.