Fishing Line Diameter Chart (Mono, Braid & Fluoro)

Thomas Krik

Written by

Thomas Krik

Marc Lowe


Marc Lowe

fishing line diameter chart

A fishing line diameter chart is a helpful resource that provides information about the thickness of various fishing lines.

When you employ the right diameter line, you can cast more accurately, with more sensitivity and less visibility to your target fish. It can also mean reeling in a trophy catch or losing it!

To help you boost the overall performance of your fishing setup, we will explain everything about fishing line diameter. Further, we will help you understand the chart and choose the perfect line thickness for any angling scenario. Without further ado, let’s dive in!

Analyzing Fishing Line Thickness


There are three common types of fishing lines, namely: monofilament, fluorocarbon, and braided. These lines differ in material composition and diameter-to-strength ratio. Understanding them and their respective sizes can help you determine the breaking strength of your line.

Below is a comparison chart showing the relative diameters of each line type:

Line Test (lb) Mono (in) Fluoro (in) Braided (in)
2 0.005 / /
4 0.008 0.007 /
6 0.009 0.009 0.005
8 0.010 0.010 0.007
10 0.011 0.010 0.008
12 0.013 0.012 /
14 0.014 0.013 0.009
17 0.015 0.015 /
20 0.016 0.016 0.010
30 0.020 0.020 0.012
40 0.024 0.022 0.013
50 0.028 0.029 0.014
60 0.030 0.032 0.015

1. Monofilament fishing line — diameter chart


Monofilament is a transparent line made of a single strand of nylon, hence, its name. These are available in various diameters and are favored for their versatility and affordable price. They also work well for lighter setups and spinning tackles.

The chart shows the mono diameter is thicker than braided lines of the same strength. Though they have a slight distinction with fluorocarbon lines, their thickness is almost the same in most given pound tests.

2. Fluorocarbon fishing line — diameter chart


Fluoro lines boast higher strength than monofilament of the same diameter. However, when you get to higher strength tests, such as 50 and 60 lb, fluorocarbon is thicker than mono lines.

Many anglers prefer fluorocarbons because they are almost invisible underwater. While stiffer and costlier than monofilament, fluoro lines offer superior performance and durability in abrasive environments.

3. Braid fishing line — diameter chart


In general, braid diameter is always lower than mono and fluoro lines. This thinner profile gives these lines a highly rated breaking strength, sensitivity, and long casting ability. The smaller diameter also allows anglers to spool more lines on their reel.

Braided lines are known to be the strongest type of line for fresh and saltwater fishing. However, they are opaque, meaning these lines are visible to fish. You’ll likely spook fish away once you use the wrong color in a specific fishing condition.

Fishing Line Test vs. Diameter — How to Use the Chart


Fishing line sizes are measured in thousandths of an inch. The smaller the number, the thinner the line — and vice versa. Similarly, a heavier-weight line will have a larger diameter than a lighter-weight line of the same material.

Using the wrong line diameter will likely impact your fishing success. For example, a thick line may intimidate fish and cause them to shy away from your bait. Thin fishing lines can snap when fighting for larger fish.

To help you analyze a thickness chart effectively, you must understand the following components of a line diameter chart:

1. Strength test or line test (LB)


This column is typically measured in pounds or LB. For instance, the thickness chart above lists the different strength categories, from 2lb to 60lb. These measurements specify the strength or pressure limit of your line.

2. Line diameter (MM or IN)


Line diameter tells you how thick a line is, compared to its strength. It’s often measured in millimeters (mm), but sometimes, it can be in inches (in).

3. PE ratings


Sometimes, some manufacturers may include a polyethylene (PE) rating. This specification measures the diameter of a fishing line but not its strength. Hence, two lines of equal PE rating may have different breaking strains.

Tips for Selecting the Proper Line Diameter


Choosing the proper line diameter is critical for optimal performance and success in your fishing endeavors. These factors will guide you in selecting the appropriate diameter for your specific fishing needs:

Fishing Technique

Your line diameter choice may also vary depending on your fishing technique. For spinning, thinner lines deliver more lure action. Fly fishing may demand thinner lines for delicate presentations.

Casting Distance & Accuracy

If you prefer finesse fishing, you should choose a thinner-diameter line. It will help you cast with greater accuracy and distance.


When fishing in clear waters or aiming for wary fish, consider using a thinner and less visible line. However, in murky waters, you can opt for slightly thicker lines without worrying as much about visibility.

Pound Test Rating

Choose a line diameter that matches the pound test rating suitable for your target species and fishing conditions.

Lighter lines are typically used for smaller fish, while heavier lines are used for larger, hard-fighting fish. Similarly, fishing in heavy cover may demand thicker lines to avoid breakage while providing greater strength.

Rod Strength and Reel Capacity

Different rod and reel systems demand a specific diameter and breaking strength. The line diameter should match the reel’s capacity while your rod is strong enough to handle the weight of the line. Hence, it’s vital to check those requirements before buying spools of the line at your local tackle shop.

Convert the Line Size

Besides considering the factors above, you need to use a diameter chart to find the suitable line size and test for your reel. From mm to lb and inches, you can find a fishing line conversion chart that compares the thickness of each line type.

As a general rule of thumb, always pick a line diameter close to the weight of your lure or bait. If your bait is ¼ oz, you may grab a 6-lb test fishing line.

Do note that the diameter vs. strength ratios can differ among manufacturers. As such, you should always check the detailed specifications of a product before purchasing it.


In essence, understanding the fishing line diameter chart and choosing the proper thickness is crucial for the overall success of your angling adventure. By considering the factors we discussed above, you can find the perfect balance between visibility, strength, and performance.

We hope this article has helped you make better decisions in choosing the proper line diameter for your fishing situation. Have fun on your next fishing trip!

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