I mean... it depends what you want to support. My web calculator [fully client side] is 370kb of JS. It has features that this doesn't have (3d rendering, solving equations), but doesn't have code that this needs (mostly, the keyboard)...

On the one hand, there's your claim that a web version of TwinCalc should be 56.3K or so. On the other hand, there's a world of existing web apps which are generally very much larger than that.

A smaller footprint than 563K would be a dubious advantage for web apps in either case.