Fish weight calculator – help you document catches

Kristian Ole



As a leading blog in the fishing space, is an excellent source of information and product reviews. Now, there is a brand new tool available for free to all anglers who may need some help.

The FishingKris fish weight calculator has officially dropped and is an excellent resource for your fishing needs. Let’s break it down.

What is the FishingKris Fish Weight Calculator?

Calculated weight


The calculator that the team created is there to get an estimated weight for a fish based on the fish type, girth, and length. Their algorithm helps give you a sense of the fish’s size without using a scale.

Just about every angler has regretted not having a scale on them when catching a trophy. By taking some simple measurements, you no longer need a scale on hand. Simply throw in some important information, and this calculator will give you a close estimate as to how large that fish would have been by weight.

Related article: The best fishing scales

What information is needed and why?

So, the length, girth, and type of fish are the three pieces of information needed for an accurate reading.


Of the three, length is the most important of the three to know. With the length and length only, you can get a general sense for how much a fish will weigh. If this is the only measurement that you can get, you will at least have a rough estimate. This paired with the other two aspects will provide you with a very accurate estimation on the weight of the fish.


Although an optional part of the calculator, measuring the girth is really important to get an accurate estimate. The girth is a measurement of around the fish at its largest point. This is a huge part of the measurement, because fish can be the same length while being fatter or skinnier than the other. This will play a big part into how much the fish will weigh, so make sure to get this measurement when possible.

Type of fish

The final part of the information section is the type of fish. Different species are made in different ways, so the measurements will be slightly skewed based on the species of the fish. The types of fish offered on the calculator include:

  • Trout
  • Steelhead
  • Snook
  • Redfish
  • Bonefish
  • Salmon
  • Bass
  • Walleye
  • Pike
  • Gar
  • Muskie
  • Sunfish
  • Bluegill

As you can see, there is a wide range of species covered by the technology. If your catch is not on this list but there is a species that is similar, use that.

Why use the calculator?

fish weight calculator - Why use the calculator? Bragging about and sharing your best fish catches

The main reason why you should use this calculator is to have closure on how big that fish probably was. It is a very tough feeling knowing that you landed a huge fish and you do not know where it falls on your best catches.

Related article: Fishing near me – interactive map

Anglers take great pride in their personal bests and what they catch. Bragging about and sharing your best fish catches is one of the best parts of fishing itself. Not knowing how big that trophy is can be super frustrating and deflating. With this calculator tool, you can get a bit of closure about the catch.

Tips for collecting data in the field

  • Use line to get the girth and length

Fishing without a scale can sometimes be frustrating when hooking into a monster. The best tip for gathering data is by cutting off some line and using that to get your measurements.

If you are fishing without a scale, there is a good chance that you are also fishing without a tape measure. So, the line is taking its place. Gather the data for girth and length with your pieces of fishing line. Cut them to the exact fish measurements. Then, when you get home, simply measure the line and you will know the metrics of the fish you caught.

  • Make sure the fish is flat and the mouth is closed

To get the most accurate results possible, make sure you are measuring the fish when it is on a flat surface and the mouth is closed. Then, measure from the end of the tail all the way up to the closed mouth. This ensures that you will not be selling yourself short for the results you could be getting.

The more accurate the measurements are, the more accurate the weight estimate is. These two factors work together, so be sure to be extra careful and get the most accurate measurements possible.

  • Take a picture of the fish next to your pole

As long as you have a phone or camera on you, this next strategy can work quite well. In order to get the length of a fish without a tape measure, you can take a picture of it right next to your rod. This will put the fish pictured with some perspective that cannot be accomplished without something to compare it to.

Having the fish right next to the rod will give you an idea of how big it is. After you are done fishing. You can analyze the picture and measure the rod to see how long it is. Then, you can compare the length of the piece of rod to how the fish is affixed to it. Unfortunately, there is no good way to measure girth with this strategy. This will not be the most accurate reading, but it is better than nothing. Then, you can plug it into the calculator and grab a weight.

Closing Thoughts

Using this fish weight calculator can make your life as an angler so much better. There is no longer the nagging feeling of not knowing the weight of a great fish when you caught it without a scale.

As long as you gather some of the key information, you have the opportunity to get some closure and be able to brag about your latest catch. So, be sure to use this fish weight calculator to take your fishing to the next level.


About Kristian Ole

Kristian Ole Rørbye, a marine biologist and seasoned angler, shares his fishing adventures and expertise on FishingKris. Join him as he explores the world's waters, one cast at a time.

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