I hope you can help me arrive at a good guess at the weight of this 21" smallmouth I caught this week on Lac La Croix in the Boundry Waters.  We didn't have a scale in the boat or a way to measure the girth, and I'd like to get a replica on the wall.

 

Any guesses?

Welcome to the forum, and congrats on a nice fish!

 

I'd guess a fairly chunky 21" Smallie would go 5lbs no problem.

5.5-5.75, I caught 2 very fat smallies that were 20" that were both 5. One was stuffed with a big crappie, the other was full of eggs, so abnormally fat. That fish looks pretty fat, and an inch longer, that's how I got my guess. 

No idea what she weighs. River Smallie 21" this time of year is much lighter for sure. Congrats and a beauty. 

 

Just giving you a heads up as to what I keep in my boat. Back years ago I bought one of those soft measuring tapes a seamstress uses for lengths and stuff they do. They are soft and coated these days where they can be wiped off before you fold it up. I forget I have it sometimes but it is accurate. Can do the same thing with a string if you have to. 

In a pinch, for future reference, you can cut 2 pieces of fishing line for length and girth and measure the line you cut to size later. Some hold up to their rod and mark the spot for length.  Nice feesh.  

Great smallie!  She seems like she has some girth, but without a measure its tough to guess. At 21", I would expect her to be over 5lbs.

5-5.5lbs. Congrats on your new PB.

Here's a 21" smallmouth that I caught, sadly it didn't break 5lbs like everyone is suggesting.  

 

 

That being said, the fish you caught appears from the photo to have more girth.  I'd be comfortable calling it a 5lb fish.

That's a stud right there, congrats! (Umm, please don't be confused. I'm talking about the fish.....)

Thanks for the help everyone.  Yes, I've learned my lesson and will be buying a soft measuring tape.

The one in my avatar was a 21" river smallie that weighed 4lb 8oz and wasn't nearly as fat as that one.  Like others have said, yours is over 5lbs easy.

i cought a 21" northen mn smallie this year and it went 5 lbs 2 oz 

here is a 21 inch lean Kansas Summer Smallmouth..it was only 4.5 lbs.