Fluorocarbon Fishing Line Diameter with Charts

Fluorocarbon line has a larger diameter than braided lines and about the same diameter as monofilament lines. Even though the line has around the same diameter it still has several advantages and disadvantages compared to a nylon monofilament line. The main advantage anglers think of with fluorocarbon is that it is more transparent underwater. This is typically the case because the index of refraction of fluorocarbon material is closer to the index of refraction of water. Thinner lines still reflect and bend less light and are more transparent. Also, the color or tint of the line can also make it less visible depending on water color and lighting conditions.

Fluorocarbon lines are only made with Fluorine and Carbon atoms. This makes the line have a higher density than monofilament. For this reason, fluorocarbon will sink faster in water, not absorb water, and not break down as quickly from UV damage. The line also tends to be more abrasion resistant but is about the same as a nylon line if the diameter is exactly equal.

The disadvantage of fluorocarbon is that it is stiff and does not have a high line stretch. Stiff lines are not good as a mainline and not as good when fishing with live bait. Monofilament leaders have high line stretch which makes them better for shock leaders. There are lots of different brands of fluorocarbon leaders and picking one with the smallest diameter should be taken into consideration when selecting a line. This is because it will likely be the least visible underwater.

Ande Fluorocarbon Leader Line Diameter

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
10	.28	.011	30
12	.30	.012	40
15	.35	.014	50
20	.40	.016	65
25	.45	.018	100
30	.50	.020	125
40	.60	.024	163
50	.68	.027	181
60	.73	.029	194
80	1.00	.039	290
100	1.08	.043	330
150	1.35	.053	430

Ande Fluorocarbon is my favorite type of leader to use for freshwater and saltwater fishing if the line is 50 pounds or under. It typically comes in red spools with clear lines. This is great leader material but the line diameter is much larger than other brands when looking at lines over 50 pounds. For example, 80-pound Ande is 1.00 mm while 80-pound Seaguar Premier is 0.78 mm.

I can still tie knots with an 80-pound Ande line but the line is noticeably thick. For leaders over 80 pounds, I will crimp the line rather than tie a knot. If you look at Seaguar Premier though the 130-pound line is only 1.05 mm which is comparable to Ande 80 pound test which is 1.00 mm. The line is made in Japan and comes in 25, 50, or 100-yard spools.

Seaguar Blue Label Leader Diameter

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
10	.24	.009	20
12	.29	.011	30
15	.33	.013	45
20	.41	.016	65
25	.44	.017	80
30	.52	.020	125
40	.62	.024	163
50	.66	.026	175
60	.74	.029	194
80	.81	.032	220
100	1.05	.041	310
130	1.17	.046	360
150	1.28	.050	400
180	1.38	.054	440
200	1.48	.058	480
220	1.66	.065	550

Seaguar Blue Label is a widely used fluorocarbon leader. Its line diameter is smaller than most other fluorocarbon lines. The Seaguar Premier does have thinner line diameters. For this reason that is typically the better line to use as it will be less visible to the fish. If abrasion resistance is important the blue label with a larger diameter is likely more abrasion-resistant.

Seaguar Premier Fluorocarbon Leader

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
12	.24	.009	20
15	.29	.011	30
20	.37	.015	58
25	.41	.016	65
30	.47	.019	113
40	.57	.022	150
50	.62	.024	163
60	.70	.028	188
80	.78	.031	210
100	.91	.036	260
130	1.05	.041	310
150	1.17	.046	360
170	1.28	.050	400
200	1.38	.054	440

Seaguar Premier has the thinnest line diameter of any fluorocarbon leader. This is a big advantage because it will be less visible underwater for a given pound test. At low pound test values, the difference is not large. For example, Ande 20-pound has a diameter of 0.40 mm while 20-pound Seaguar Premier has a diameter of 0.37 mm. For a higher pound test, the difference becomes quite significant. For instance, 80-pound Ande has a diameter of 1.00 mm while 80-pound Seaguar Premier has a diameter of 0.78 mm.

This thinner diameter also makes it easier to tie knots. Leader lines can be attached to a braided line with a line-to-line connection. When fishing mono or a fluoro leader on a lure it is typically attached with a crane or barrel swivel. A common leader length for trolling lures is 6 feet but varies depending on the type of fish being targeted. Anglers targeting mutton snapper typically use leaders over 30 feet long and up to 80 feet. This is because they are very leader-shy fish that live in clear water and will not typically bite if the bait is not presented in a natural way.

Yo-Zuri HD Diameter Chart

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
12	.34	.013	45
15	.41	.016	65
20	.44	.017	80
25	.48	.019	113
30	.57	.023	156
40	.62	.024	163
50	.71	.028	188
60	.78	.031	210
80	.88	.034	240
100	.98	.039	290
130	1.23	.048	380
150	1.30	.051	410
200	1.48	.058	480
300	1.83	.072	620

Yo-Zuri HD is one of the thickest leader lines at the 20-pound test value but comparable to other high-end leader thicknesses at 80 pounds and above. It is marketed as a soft line that is made in Japan. It comes in clear and pink. I use a clear leader and do not think that pink leaders are less visible. This is because the pink color disappears under 20 feet but it actually turns to a tint of gray. In general, a clear or light color line is less visible underwater. I stay away from dark-colored fishing lines for braid, mono, and fluoro leaders. Pink is not super dark but still likely not helpful and the color is a line impurity that can decrease the line strength.

Hi-Seas Fluorocarbon Leader Diameter

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
12	.30	.012	40
15	.35	.014	50
20	.40	.016	65
25	.45	.018	100
30	.50	.020	125
40	.60	.024	163
50	.70	.028	188
60	.75	.030	200
80	.90	.035	250
100	1.00	.039	290
130	1.20	.047	370
175	1.35	.053	430
220	1.50	.059	490
280	1.70	.067	570
330	2.00	.079	690

Hi-Seas leader line diameter is average when comparing it to the diameter of other lines. It is made with 100 percent fluorocarbon as are most other leaders. For this reason, it will have a similar performance to others made with the same material. How a line is manufactured does change the properties slightly but mostly is just marketing tactics to say one is better than the other. However, the line diameter is one way to objectively compare leaders at a given pound test.  Hi-Seas is an American company but the line is made in Portugal.

Berkley Pro-Spec Diameter

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
20	.46	.018	100
25	.51	.020	125
30	.56	.022	150
40	.61	.024	163
50	.74	.029	194
60	.81	.032	220
80	.91	.036	260
100	1.04	.041	310
130	1.17	.046	360
150	1.27	.050	400

Berkley Pro-Spec has the largest 20-pound leader diameter. This is not typically a good thing. At a high pound test rating the line diameter does become competitive with others but is still on the thick side. It is marketed for having high durability and crimp strength which is likely true. The line is made in the USA. For low line visibility, the Berkely vanish is a better option and is also made in the USA.

If you just want a tough abrasion-resistant line for fish that are not leader shy then Berkley Pro-Spec is a good option. Fish that require a line with high abrasion resistance include tarpon, snook, sailfish, swordfish, marlin, and even large bass. These fish have mouths that are rough like sandpaper. Fish that have sharp teeth like sharks, barracuda, wahoo, mackerel, pickerel, pike, and musky require a steel leader.

Berkely Vanish Line Diameter

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
2	.15	.006	10
4	.18	.007	12
6	.23	.009	20
8	.25	.010	25
10	.28	.011	30
12	.30	.012	40
14	.33	.013	45
17	.38	.015	58
20	.41	.016	65

Berkely Vanish comes as a fluorocarbon fishing line and as a leader line. The bulk spools of the fishing line actually work well as a leader material as well. The mainline material is not stiff and is soft like a monofilament line. This is the type of line I like to use for trout fishing in streams and snapper fishing on the ocean.

The line is actually not as thin as other leader lines but is flexible and abrasion-resistant. The line is also dense which means that it will sink faster in water. This is nice when fishing with soft plastics for bass as the lure will sink faster without adding weight. The line is made in the USA and will work on baitcasting and spinning reels.

Seaguar Red Label Fishing Line

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
4	.17	.006	10
6	.19	.007	12
8	.24	.009	20
10	.26	.010	25
12	.31	.012	40
15	.33	.013	45
20	.41	.016	65

Seaguar Red Label is a fluorocarbon mainline. It is soft and flexible enough to work for spinning reels and baitcasting reels. The 20-pound red label line is not as thin as Seaguar Premier but this line come in a lower-pound test value all the way to a 4-pound test. Thinner lines are going to be less visible so using a lower pound test will typically get more leader shy fish to bite. This line has less stretch than monofilament but more stretch than braid. It only comes in line strength up to 20 pounds because heavier lines would not be soft and flexible enough to work great as a mainline.

P-line Fluorocarbon

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
6	.22	.009	20
8	.26	.010	25
10	.28	.011	30
12	.30	.012	40
15	.35	.014	50
17	.39	.015	58
20	.42	.016	65

P-line is 100 percent fluorocarbon and is made in Japan. Overall this line has an average diameter compared to other lines. It only comes in line rated from 6-20 pound test.

P-line Fluorocarbon Coated

Fluoro Pound	Dia (mm)	Dia (in)	Braid Equiv
2	.13	.005	8
3	.15	.006	10
4	.18	.007	12
6	.23	.009	20
8	.25	.010	25
10	.29	.011	30
12	.31	.012	40
15	.36	.014	50
20	.41	.016	65
25	.46	.018	100
30	.50	.020	125

P-line Floroclear is a fluorocarbon-coated monofilament line. This is done to try and decrease the visibility of the line. In practice though, it does not change the index of refraction of the monofilament line so very likely has similar properties to standard monofilament lines. I do not like to use fluorocarbon-coated lines.

Fluorocarbon Line Visibility

Fluorocarbon is typically less visible underwater since the index of refraction is 1.42 this is closer to the index of refraction of water which is 1.33. Standard monofilament has an index of refraction of around 1.55.

If the line rubs on the mouth of a fish or on the ground it tends to get rough and is actually very visible to fish. For this reason, the end of the leader should be monitored to make sure the line looks clear. Sometimes dirt and slime in the water can also build up on the line. If this happens wipe the line down with a cloth to help the line stay clean.

The video above looks at the fishing line’s visibility underwater. A fluorocarbon line is not invisible underwater but the thinner it is the less visible the line should be. There are other factors but the fishing line diameter plays the greatest role in differences in line visibility when the line is the same material and color.