Beginners or novices to fishing have confusion about all aspects of the sport. This includes the fishing line. Beginners often do not know what size fishing line to use. The size or strength does matter when fishing. A line too strong is heavier. It will reduce the number of bites. A line too light will break easily.

The type of line has an effect on the line strength. As an angler, you want optimum strength to diameter ratio. In other words, a strong thin is best. Plus the line needs to have the characteristics for what environment you fish. A braided line has the best ratio but is not ideal in rocky or heavy brush areas. Monofilament and fluorocarbon have some problems also.
Anglers must choose the correct line for the environment. Then choose the correct line before determining what test strength (size) of the line. Choosing the right line for the conditions is more important than test strength in many instances. After choosing the right line. You can pick the right size fishing line to use.
Fishing Line Size
The following chart shows the recommended strengths for many North American game fish. The strength of a line needs adjusting in some situations. Fishing in heavy or areas with abrasion, a heavier line is recommended. In clear waters, a thinner line is preferred.
Species | Mono | Fluoro | Braid |
Trout or Panfish | 2-6 | 2-6 | 10-15 |
Bass, Largemouth or Smallmouth | 8-14 | 6-14 | 20-50 |
Catfish | 14-30 | N/A | 20-50 |
Walleye | 6-12 | 6-12 | 15-30 |
Pike or Musky | N/A | Leaders | 50-100 |
Carp | 8-12 | 8-12 | 20-50 |
Diameter comparisons of the fishing lines. These are general specifications. The actual size or rating may vary some between manufacturers. The list is not all-inclusive. It gives the diameter for common strength lines.
Line Strength lbs. | Mono | Fluoro | Braid |
4 | .008 | .007 | |
6 | .010 | .008 | .005 |
8 | .011 | .009 | |
10 | .012 | .011 | .009 |
12 | .014 | .012 | |
14 | .015 | .013 | |
17 | .016 | .015 | |
20 | .018 | .017 | .009 |
30 | .022 | .020 | .011 |
40 | .024 | .023 | .012 |
50 | .028 | .025 | .014 |
65 | N/A | .028 | .016 |
80 | .035 | .030 | .018 |
100 | .039 | .036 | .020 |
Line diameter has an effect on performance. As mentioned, thinner lines cast farther. Thicker lines have better shock strength and abrasion resistance. An angler needs to consider the structure and cover. Areas with weeds, thinner lines are best. In rocks and brush, abrasion resistance is a must.
Choosing a Line
Using braid, a fluorocarbon or monofilament leader is recommended. This allows an angler to benefit from the characteristics of the line. The mainline is thin. The line in the cover is thicker with abrasion resistance.
Beginners should talk to anglers in their area. The experienced angler will share recommendations on line type and strength. Look on social media or ask other anglers while fishing. The majority of anglers will be happy to share information. Do not go overboard. Ask a few questions and wait until next time to ask more questions. Remember they are there to enjoy the outing.
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Summary
Choose a line with the help of the charts above. The type of line should be based on ability and specific needs in a line. Fluorocarbon is rarely a good choice for a mainline. Monofilament is inexpensive and easy to tie knots. Braid offers durability, strength, and sensitivity.
Learn what line other anglers use for your target species. Choose the size according to the fish size. In doubt go with a middle-sized line. The right fishing line makes fishing more enjoyable.
John McIntyre