Have you ever found yourself fishing on a remote body of water and caught a high quality bass but didn’t have a scale to find its weight?
I know I have …
One several occasions during my early days of bass fishing, I would just mentally estimate the weight of the fish for the future stories of battling the behemoth bass.
After all, what are great fishing tales made of anyway 😉
Getting Closer to the Truth About Trophy Bass Catches
Even though there are a number of decent, relatively low-cost digital scales on the market today, there will still be times when you land a quality largemouth or smallmouth and still want a “real” weight estimate.
Fortunately, there have been a number of formulas developed to help bass anglers estimate weight using two simple measurements on the fish: the length and the girth.
In order to get the best weight estimate possible, it is use the proper procedure for taking each measurement.
The length of a bass is the distance between the tip of the lower jaw (with mouth closed) and the longest point of the tail. Girth on the other hand is determined by measuring the circumference of the fish around its widest part (usually the gut).
Here is an image to assist in taking the measurements properly:
Once the length and girth are recorded, it is a cinch to visit one of the numerous bass fishing-related websites with an online weight calculator (search Google for bass weight calculator).
Another option is to just enter the following formula into your calculator (or even the Google search engine) to obtain an estimate of the weight in pounds:
Bass Weight Estimate (lbs.) = (Length * Length * Girth) / Shape Factor
(Shape Factor = 1280)
As an example, let’s say I caught a largemouth where the length is 24″ and a girth of 16″ (which I have!)
To calculate the weight multiply …
24 x 24 x 16 = 9216 which is then divided by the Shape Factor of 1280 …
9216 / 1280 = 7.2 lbs
The actual weight of that fish on a certified scale was 7.19 lbs… Close enough in my book 🙂
Write the formula down on the back of a business card (or your fishing license) and you’ll even be ready to use it in the field with your cell phone!