[directionless]

For calculator languages, I think there are several choices. Depends a bit on what you know, and what you need...

Frink (https://frinklang.org/) has been around for ages, and is rooted in physical unit conversions

Calca (http://calca.io/) has come up a handful of times. It looks pretty reasonable

R, if that's your flavor

Anything with a REPL. Though the OP suggests these are cumbersome, I'd counter argue that anything you know well is usually more efficient than learning something new.

A very long list of commercial tools: Matlab, Mathematica, WolframAlpha, STS, SAS, etc