I would say a card has a toy limit if it doesn't provide enough credit for the customer to comfortably charge and pay-in-full his monthly expenses with one payment.

If we're looking for a reasonably objective definition of "toy limit", I'd say this is it.

There's still going to be some variance based on one's lifestyle and geographic location, but this makes a good rule of thumb.

Could the average single person put all of their monthly expenses other than rent/mortgage on that card and be within that limit? If not, it's a "toy" limit.

For a college kid spending a gap year living in Thailand, that $500 Capital One card is hardly a "toy" limit since her expenses are easily going to fit within that limit.

But for any typical single person living in a mid-size or larger US city, however, the same card is probably a "toy".

As for those who adjust their perception of toy limits as their own credit limits increase, I respectfully submit that perhaps we should have a different term. When your max limit is $9000 and you get a $2000 CL on a new card, that's not really a useless limit, but it certainly feels like an affront.

Ergo, I suggest that perhaps the true bon mot for those situations is: insulting limit.