Do you have trouble visualizing sizes when doing digital design work or buying things online?

I sure do.

Best solution I've found is also hilariously simple: I keep a retractable tailor's tape within arm's reach of my desk, and whip it out for reference whenever I'm unsure (i.e. almost every time).

@starkatt This is such a common problem for electrical engineers that you can get these little pcb rulers with actual component footprints on them so you can see what they look like and how they compare to each other

they usually also have other useful stuff on them like trace widths and stuff, too
-F/R

@Felthry I love that ruler, have one myself.

@Felthry 'cause yeah there's no inherent size reference when looking at a PCB layout!

@Felthry ...looking at the picture I'm like "owo coin for scale isn't so useful when it's not a known coin", then realized wait, ruler for scale.

@starkatt it seems like the ruler is the thing being shown here as the coin is partly obscured; this was a random search result so it's possible the coin is common to the clientele of the site this came from
-F

@Felthry I figure it is, yeah. Mostly noting that coins aren't a great scale reference.

(my go-to for that size range is an AA battery.)

@starkatt I wonder just how recognised American coins are elsewhere in the world for exactly this reason?

A AA battery is probably a good option. They're used all over the world and have a specific fixed size by necessity. Lacking any other sense of scale though, you would have to make sure to note that it's a AA and not a AAA.
-F

@Felthry @starkatt Americans have coins?