Global Moderator 12poundbass Posted December 20, 2016 Global Moderator Posted December 20, 2016 I was watching Bill Dance's show the other night and he was talking about a way to estimate a fish's weight only by length. Here's what he explained...the fish is 20" multiply 20x20x20 then divide by 1600. Always divide by 1600. I was wondering if anyone has tried this and if it's fairly accurate. I caught a nice one last year and went to weigh it and my batteries were dead in my scale! If this is fairly accurate it would be pretty handy since most fisherman have a ruler. I don't carry a tape to do the length/girth formula (although I guess I should if I want a replica mount). I haven't tried it yet (iced out in Michigan) and wondering if anyone has?
riverbasser Posted December 20, 2016 Posted December 20, 2016 Its about as accurate as me asking your height and then guessing your weight based on the average of people that are the same height. I made be dead on or way off. Too me there is no substitute for a scale. I've caught 23" bass that weighed 4lbs. By his formula I should have a new PB 4
Super User roadwarrior Posted December 20, 2016 Super User Posted December 20, 2016 http://www.bassresource.com/bassfishing/fishcalculator.html
Super User J Francho Posted December 20, 2016 Super User Posted December 20, 2016 The only time I use length is when I'm fishing an online kayak tournament, where length is how contestants are scored. Otherwise, it's always mass. If you want to know the fish's mass, weigh it. 1
Super User WRB Posted December 20, 2016 Super User Posted December 20, 2016 Most bass weight calculators that only use length assume the girth is 75% of the length*. * length being bass laid flat measure from end of closed mouth to end of tail. If I use the BR site calculator and add girth my PB** weighs 23.08 lbs!....would a world record! Length X Length X Girth /1200 is more accurate, still no substitute for a certified scale weight. Tom ** 29" L X 28" G, actual weight 19.3 lbs. 6
Global Moderator 12poundbass Posted December 20, 2016 Author Global Moderator Posted December 20, 2016 This is exactly why I asked. Conclusion...carry extra batteries! 1
Super User MIbassyaker Posted December 20, 2016 Super User Posted December 20, 2016 26 minutes ago, 12poundbass said: I was watching Bill Dance's show the other night and he was talking about a way to estimate a fish's weight only by length. Here's what he explained...the fish is 20" multiply 20x20x20 then divide by 1600. Always divide by 1600. I was wondering if anyone has tried this and if it's fairly accurate. I caught a nice one last year and went to weigh it and my batteries were dead in my scale! If this is fairly accurate it would be pretty handy since most fisherman have a ruler. I don't carry a tape to do the length/girth formula (although I guess I should if I want a replica mount). I haven't tried it yet (iced out in Michigan) and wondering if anyone has? I have checked this against the largemouth I catch in lakes around our area, and I have found it overestimates the weight for the vast majority. for instance, the formula estimates 16" bass to be about 2.5 lb. The ones I catch are more like 2.25. 20" by the formula is a 5lber, but my 20" bass are closer to 4.5. 1
Global Moderator 12poundbass Posted December 20, 2016 Author Global Moderator Posted December 20, 2016 That's not too far off unless the difference gets bigger the longer the fish. Maybe it's a little more accurate for northern bass since their growing season is shorter, or maybe I'm looking too far into it. Either way I'm packing an extra set of batteries just in case they die on me again. Then again since fisherman always "lie" you could use it to your advantage and tell your buddy I caught a 10 pounder just do the math! Lol!
Red Bear Posted December 20, 2016 Posted December 20, 2016 keep extra scale batteries, or keep a $5 backup spring scale with you.
Global Moderator 12poundbass Posted December 20, 2016 Author Global Moderator Posted December 20, 2016 1 hour ago, Red Bear said: keep extra scale batteries, or keep a $5 backup spring scale with you. I wasn't a big fan of the spring scale. I noticed that you could fudge it fairly easily. That's why it's now a toy for my son and I'm packing extra batteries as soon as I get home before I forget.
Super User J Francho Posted December 20, 2016 Super User Posted December 20, 2016 My Chatillon spring scale is more accurate and consistent than any digi-scale. There was a review recently of a baggage scale from Amazon or something that was very accurate, and inexpensive. 1
Super User Team9nine Posted December 20, 2016 Super User Posted December 20, 2016 I do it frequently on bass when I just want a good general idea of fish weight. However, I don't follow the generic formulas listed above. Instead, I use a standard weight table that runs in 1/4 inch increments as calculated by local and regional biologists. Not good enough for big bass or PBs, but plenty good enough for everything else. Contact you local DNR to see if they have a specific std wt table for your local waters.
RHuff Posted December 20, 2016 Posted December 20, 2016 Just go with 20 inches is roughly 5lbs..... You can adjust the ratio accordingly.
Super User Catt Posted December 20, 2016 Super User Posted December 20, 2016 4 hours ago, WRB said: Most bass weight calculators that only use length assume the girth is 75% of the length*. * length being bass laid flat measure from end of closed mouth to end of tail. If I use the BR site calculator and add girth my PB** weighs 23.08 lbs!....would a world record! Length X Length X Girth /1200 is more accurate, still no substitute for a certified scale weight. Tom ** 29" L X 28" G, actual weight 19.3 lbs. Exactly! It also depends on the individual bass, some are short/fat & some are long/slim. This bass was over 30" in length which is longer than WRB's be didn't have his girth so it only weighted 11 lb 3 oz.
Super User J Francho Posted December 20, 2016 Super User Posted December 20, 2016 21 minutes ago, Catt said: only weighted 11 lb 3 oz. Pffft! Nice dink, Catt. 3
IndianaFinesse Posted December 20, 2016 Posted December 20, 2016 Just don't use the weight calculator here on bassresource, that way overestimates the weight. I've tested it against my scale, and it showed that for the length and girth of a bass that I knew weighed 2.4 pounds, it said it weighed 4.1 pounds! I've also tested it against several other fish, and each time it guessed the weight to be nearly double the actual weight of the fish. I used that calculator on what I thought to be my pb a couple years ago before I bought a scale, and it showed it to be 10.3 pounds. Looking back on it, it probably only weighed around 6 pounds, so I guess I should change my "pb" to an 8.2 pounder that I caught and weighed on a scale.
Dogmatic Posted December 20, 2016 Posted December 20, 2016 I think I posted this before, but this is put out by the PAFBC, and this past season we checked it against our fish and found it "relatively" accurate. Take in account this is for Northern strain, and season.
Red Bear Posted December 21, 2016 Posted December 21, 2016 21 hours ago, 12poundbass said: I wasn't a big fan of the spring scale. I noticed that you could fudge it fairly easily. That's why it's now a toy for my son and I'm packing extra batteries as soon as I get home before I forget. what do you mean by fudge it exactly? just make sure it is set to zero before you weigh the fish, its not hard at all. id probably trust my spring scale more in the long run than i trust a digital. too many things could go wrong with a digital and the electronics in it. even a low battery could possibly give you wrong weights. not saying digital scales are garbage or even frequently wrong by any means, just that i would put more faith in my spring scale. just because something costs more and/or is more advanced technologically doesnt mean its better... 1
Super User the reel ess Posted December 21, 2016 Super User Posted December 21, 2016 23 hours ago, Red Bear said: keep extra scale batteries, or keep a $5 backup spring scale with you. I'd trust the length-only method more.
Red Bear Posted December 21, 2016 Posted December 21, 2016 Just now, the reel ess said: I'd trust the length-only method more. too unreliable. you have short fat bass, long skinny bass, short skinny bass, long fat bass...too many variations to trust only length. there is nothing wrong with spring scales at all. i know i said 5 dollar in my post, but thats as a back up plan to digital, but you cant deny boga grips have quite a good reputation
Super User the reel ess Posted December 21, 2016 Super User Posted December 21, 2016 3 minutes ago, Red Bear said: too unreliable. you have short fat bass, long skinny bass, short skinny bass, long fat bass...too many variations to trust only length. there is nothing wrong with spring scales at all. i know i said 5 dollar in my post, but thats as a back up plan to digital, but you cant deny boga grips have quite a good reputation Spring scales are almost always wrong and that will be in one direction so that everything you weigh will weigh either lighter or heavier than it really is. At least the length average is dead in the middle of the bell curve.
Super User J Francho Posted December 21, 2016 Super User Posted December 21, 2016 1 minute ago, the reel ess said: Spring scales are almost always wrong and that will be in one direction so that everything you weigh will be either lighter or heavier than it really is. At least the length average is dead in the middle of the bell curve. Depends on what spring scale you're using. Boga's are pretty accurate. Chatillon are the standard that any scale is held to. I trust my Chitillon over any "digital" scale any day. The only issue is reading an analog scale - you have to watch out for parallax. I think many confuse accuracy with resolution. Just because a scale carries out and rounds to 1/100 oz. doesn't mean it's more accurate. 1
Super User the reel ess Posted December 21, 2016 Super User Posted December 21, 2016 Just now, J Francho said: Depends on what spring scale you're using. Boga's are pretty accurate. Chatillon are the standard that any scale is held to. I trust my Chitillon over any "digital" scale any day. The only issue is reading an analog scale - you have to watch out for parallax. I think many confuse accuracy with resolution. Just because a scale carries out and rounds to 1/100 oz. doesn't mean it's more accurate. He said the $5 spring scale
Super User J Francho Posted December 21, 2016 Super User Posted December 21, 2016 1 minute ago, the reel ess said: He said the $5 spring scale I quoted you. You said "spring scales." Here's a link to Chatillon: http://www.chatillon-scales.com/weighing-solutions/fish-and-game-scales/in-series.aspx This model work for most, though you might want to go to a higher max load, depending where you live: https://www.amazon.com/ScalesGalore-Chatilllon-IN-12-Fishing-Scale/dp/B000235XFC/ref=sr_1_9_a_it?ie=UTF8&qid=1482341428&sr=8-9&keywords=chatillon+scale
Super User the reel ess Posted December 21, 2016 Super User Posted December 21, 2016 6 minutes ago, J Francho said: I quoted you. You said "spring scales." Here's a link to Chatillon: http://www.chatillon-scales.com/weighing-solutions/fish-and-game-scales/in-series.aspx This model work for most, though you might want to go to a higher max load, depending where you live: https://www.amazon.com/ScalesGalore-Chatilllon-IN-12-Fishing-Scale/dp/B000235XFC/ref=sr_1_9_a_it?ie=UTF8&qid=1482341428&sr=8-9&keywords=chatillon+scale And I quoted him. He was referring to a backup $5 scale
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