How do metric-users casually describe intermediate distances?

I'm writing SciFi in a hypothetical future where we Americans have finally switched to metric (hey, it's my world, I can make believe).

But being myself acculturated in imperial-units America, I'm having a hard time figuring out how to describe certain kinds of distances.

If something is a couple centimeters, no problem. If it's a couple meters, no problem. But what about something in between?

For example:

The ball bounced a few inches off the table.

I'm picturing six inches in my head. That's more like fifteen centimeters. If I said "a few centimeters" then it's not enough. But saying "it bounced fifteen centimeters" off the table is far too formal and precise.

So, how would a metric user conversationally describe a distance like that?

Another example:

The box was a couple feet wide.

I'm picturing 18 - 30", or 45-76cm. Would a native metric speaker just say "about a half meter?"

That sounds better and makes more sense to me, so I guess it's not as much of a problem.

Still, for the non-Americans out there, what do you use, conversationally, to describe intermediate distances that are more in the range of 10-35 cm, or 65-85cm, where "a couple inches" or "a couple feet" would be pretty accurate but "a couple centimeters" or "a couple meters" would not be.

Do people ever say "decimeters?" I've never heard anyone actually say that one, though it does fit the use case.

Thanks!

Solution 1:

An interesting question that made me question my own usages (being from the UK, a supposedly metric country) and it made me realise it's not easy to answer.

As I am of a certain age I will freely mix my standards and will talk about "a few centimetres" when the distance is small, or "a few inches" when the distance is greater. Similarly I might talk about "a couple of feet" or "about half a metre" depending on my audience (former=older, latter=younger)...

But I suspect younger people may not have an appreciation of what an Inch actually looks like, other than by inference.

I can certainly visualise myself saying something like twenty or thirty "centimetres or so.." for the 5-6 inches distance. Or "around 20 centimetres..", or indeed any terms that imply "approximation"...

I have never ever heard anyone use the term "decimetres" though I know it is a perfectly accurate unit of length.