Speaking of literate-calc mode is AMAZING for these sorts of things. It lets you use emacs-calc in a notebook, so you get units, unit conversions, solving. It's great for quick calculations and units make sure you know immediately if you need to divide or multiply.

I use it all the time to make benchmarks for how long something will take, the memory, etc

(Just add this for unit conversions

``` (after! calc (defalias 'calcFunc-uconv 'math-convert-units)) ``` )