How big do guppies get?

I was at the FS today and saw the biggest guppies I'd ever seen. More like molly-size. So I asked the guy if they were guppy/mollies and he looked at me like doh! They're always so big when they're adults he said (he WAS quite rude, but hey, so are most FS employees in my experience, so nothing new). So how big do they get (the adults, I mean). These must have been 3in or something.

 

I have a couple of three year old females here that are about 3 inches.

Most guppies, however, do not get that large.

 

Thanks, Dino. That's what I thought. 3in seems really large.

 

Several of the specific strains do get larger.

Moscow strains ( blue, purple, green, black) and some strains of half blacks get to larger sizes.

Most guppies get to about 2 inches.

 

They were dark blue (whatever strain that is). Veeeery pretty too.

 

Probably the blue Moscows.