Shout out to https://instacalc.com/ . It's like a simple spreadsheet or calculator but with awesome support for dimensional analysis -- you can attach any units you want to a quantity and it will track it throughout the calculations. For example, here's a quick scratchpatch I used for calculating memory bandwidth / CPU transfer rates: https://instacalc.com/56842. - Source: Hacker News / 9 months ago

Neat! I used to use https://instacalc.com/ for simple calculations, you can share your calculations, but it doesn't have the notepad feature like this one. - Source: Hacker News / over 1 year ago

In the wide niche on the complexity scale between your basic Windows* calculator and MATLAB sits instacalc.com. Source: over 2 years ago

For quick ad-hoc calculations I like https://instacalc.com/ because:. Source: almost 3 years ago

Surprised no one has mentioned https://instacalc.com yet. Not a native Mac app but genius. - Source: Hacker News / about 3 years ago

I'm a huge fan of assistive note pads. I wish the one I use was more stable and supported multiple files and more solvers: https://parnold-x.github.io/nasc/ Hopefully more tools like this and the OP come out. - Source: Hacker News / almost 3 years ago