How much does a 20 inch large mouth bass weigh?

Approximately 4 lbs. Like the guys say, you need a girth measurement. You can do this with a piece of line and measure it later if you don't have a tape handy. Nice catch!

Largemouth Bass Weight

if you are a self proclaimed semi pro you should know. But really since you aren't, go to the library and read all about all the semi stuff you need to know about. Or don't! You might learn something, and reading about anything and everything is free. I suggest reading about both species even doing so on line on wikipedia would be a huge improvement from here-say you'll get here or anywhere. if you really hate libraries or you can't read it might be worth your while to at least learn to hit spell check. Just that everything worth remembering you (everyone) needs to write down. The brain holds on to 60% more when it's written down so take some notes about the different types of baits, at what depths you need to present them at, in what colors they work best at all the different depths and in all the differentiating certain ways you can rig, present and retrieve them at. Not to mention water clarity time of day water temperature and sunny or cloudy conditions. If you want to become a semi pro because you sacrificed a little time to be better at something you wanted to become better at. I commend you for that effort as learning is a very rewarding result of studying, I suggest reading books by the bass pros as well.

depends on available forage (if well fed or not so well fed) also depends on where in the world you are a 20" large-mouth in Minnesota might be 6-9 years old but in Florida only 4-6 This along with male or female is an abundance of possibilities So, this leaves a slot in my estimation. figure between 3 and 5 pounds

Very nice catch my friend, i caught a 21" today also, it gave a real good fight, and the answers u got are correct, anywhere from 4 to 5 pounds, mine weighed in at around 5 to 5.5! But very nice catch, Good Luck next time!!! Happy fishing!

Would have ta' know her girth size ta' get somewhat of an approximation. Here's an Online calculator (somethin' like AIRFLOW mentioned) so if ya' run into the same situation again you can refer to it ;)... < ' ( (( > <

http://www.fishingreporters.com/fish-calculators/

"Lucky to land it", yup' Bass can be real scrappy s_ _ k_ _ s on light riggins', especially them Smally's ;)...

Here is a converter, from mepps, works in cm

Link isn't working, search for mepps.com and look under weight calculator.