What Pound Test to Use for Trout [Complete Guide]

Fishing line is one of the most fundamental and important pieces of fishing equipment for any trout angler. It allows you to effectively fish different baits and lures and is your direct connection to the fish. Having the right type and size of line is extremely important and can ultimately make a huge difference. 

If you are new to fishing or are trying out a new lure or technique you might be wondering what pound test of line you should be using for trout. This is an important question, and the right answer may vary depending upon a few different factors.

When fishing for trout the best pound test line to use is 6lb fluorocarbon. It’s the most versatile line strength and will be effective in most trout fishing situations. If you are targeting larger trout or fishing in a river, I’d recommend using 6 to 8lb test. When fishing for smaller trout you can get away with using 4lb test.

With that being said each trout fishing method and technique might call for a slightly different line size and type. If you would like to learn more about how to choose the right fishing line for trout, please continue reading below.  

What Pound Test to Use When Targeting Trout

If you have ever looked online or at your local sporting goods store for fishing line, you’ll notice that there are a ton of fishing line options you can choose from. With so many choices in can be difficult to know which line you should use when fishing for trout.

Afterall there are a lot of things to consider, and the right line size may be different depending upon which trout you are targeting and the body of water you are fishing.

To help make sure you select and fish with the right line size on your trout fishing adventures, I’ve put together the following table.

Trout Fishing Line Size Guide

Trout SpeciesLine SizeLine Type
Small Trout4-6lbFluorocarbon or Monofilament
Large Trout6lbFluorocarbon or Monofilament
Trout in Rivers6-8lbFluorocarbon or Monofilament
Lake Trout30-40lb braid + 12lb fluoro leader or 20lb straight fluorocarbonBraid + Fluorocarbon or Monofilament leader or straight fluorocarbon

Now that you have a basic understanding of what line size you should use in different situations, let’s talk about the specific species and what pound test you should use for each one.

Rainbow Trout

When fishing for rainbow trout the best line to use is 6lb fluorocarbon. This line size is ideal for fishing with spinners, spoons, PowerBait and other popular trout fishing methods. If you are fishing for rainbow trout in a river with strong current, I’d recommend upsizing your line size to 8lb test. The extra strength will allow you to fight and land more rainbows in heavier current. When fishing for stocked or smaller rainbow trout you can get a way with using 4lb line, but I’d recommend just sticking with 6lb test.

Brook Trout

Brook trout are generally smaller than most other trout species, but they can put up a pretty good fight. Due to their size it’s best to use light line. The best size of line to use for brook trout is 4-6lb test. For larger and stronger brook trout 6lb test is ideal. When fishing for smaller brook trout 4lb test is best and all you’ll need.

Brown Trout

Brown trout typically range from 7 to 14 inches with trophy size brown’s reaching up into the 20’s. The best line size to use for brown trout is 6-8lb test. Brown’s can be pretty aggressive and are known for putting up a big fight. If targeting smaller browns 6lb test can work great as well. When going after trophy browns 8lb test is recommended.

Lake Trout

Lake trout are one of the largest species of trout and can weigh between 15-40lbs. Due to the size of these fish heavier line and tackle is required. Due to their size the best pound test line to use for Lake trout is 20+lb fluorocarbon or 30lb braid with a 20lb monofilament or fluorocarbon lender. This heavier line will allow you to effectively catch and land lake trout.

Check out this article for more guidance on how to choose the right fishing line for each species and fishing technique: What Pound Test of Fishing Line to Use [Complete Guide]

Best Trout Fishing Line

Over the years I have spent thousands of hours with a fishing rod in my hand while targeting a variety of trout species. From my experience the best overall fishing line to use for trout is fluorocarbon. It’s essentially invisible, it sinks and is much more sensitive when compared to monofilament.

Some anglers prefer to use a braided main line and a fluorocarbon leader, but I’ve found using straight fluorocarbon much simpler and effective. We will cover the pros and cons of each trout fishing line a bit later.

Here are my go-to fishing lines to use when I’m fishing for trout:

How to Choose Trout Fishing Line

Using the right type and line strength is really important when fishing for trout and can be the difference between catching and loosing fish.

As I mentioned previously the right type and pound test to use for trout depends upon several factors including the caliber of trout you are targeting, type of lures you’re using, and the cover and water you are fishing at.  

Here is exactly what you need to know about the different line types, how to choose the right line, the importance of pound test, and which line you should use for each trout fishing rig and technique.

Line Strength

The strength of a fishing line is measured by how many pounds of force it takes to break the line. The larger the pound test of the line means the more force it can take without breaking.

The downside to larger line is that has a bigger in diameter, is more visible and tends to make baits look unnatural. On the other hand, if you choose fishing line that has too small of pound test you can easily break off and loose fish. That’s why having the right balance is key.

Before you purchase fishing line consider what size/weight of the lures you are using, caliber of fish you are catching. For larger lures and trout 6-8lb is a perfect choice. When fishing with small baits and lures 4-6lb is best.

Fishing Line Type

There are three main types of fishing line that are used in for trout. Monofilament, fluorocarbon, and braid. Each one proving anglers with different advantages and disadvantages.


The fishing line I probably use the most is fluorocarbon. It has a smaller diameter when compared to monofilament, has less stretch, it sinks, and is a lot more sensitive.

Fluorocarbon is also nearly invisible in the water which makes it a great choice in clear water. Fluorocarbon is always my preferred choice when fishing for trout and would recommend it to any angler.


Monofilament has been the original fishing line material and has been around for what seems like forever. It has the largest diameter when compared to the other fishing line types and also has the most stretch. Monofilament is also a floating line and is pretty good at abrasion resistance.

If you are fishing with PowerBait or some type of live bait like worms Monofilament can be a great option. Its affordable, easy to find and works great for these trout fishing applications.


Braided fishing line gives you the ultimate strength with zero stretch and has a really small diameter given its strength. This combination makes it great as a main line and when fishing heavy lures around grass and other cover.

However, it’s also highly visible in the water and can shy away fish. For this reason, I’d only recommend using braid as a main line and paring it with either fluorocarbon or monofilament leader.

Trout Fishing Line by Technique

Just like a lot of other types of fishing there are several different techniques, baits, and rigs anglers can use when targeting trout. With so many options to choose from it can be hard to keep track of what line size you should use for each angling method.

To helps with this here is a breakdown of what pound test you should use for each different trout fishing technique:

Angling MethodPound TestLine Type
Crankbaits4-8lbFluorocarbon or Monofilament
Live Bait4-8lbFluorocarbon or Monofilament
Ice Fishing4-6lbFluorocarbon
Trolling6-10lbFluorocarbon or Monofilament
Jigs/Tubes6-8lbFluorocarbon or Monofilament

Spinners & Spoons

Using spinners and spoons can be a great way to catch trout in most any body of water. The flash, vibration and action make them hard to resist. When using these types of lures, I would recommend using 4-8lb fluorocarbon line. For heavier spinners and spoons 6-8lb test is ideal. When fishing with light and smaller sized lures 4-6lb test is preferred.


Casting and cranking a Rapala or similar style crankbait can be a great way to catch trout. For this technique I’d recommend using 4-8lb test depending upon the size of your crankbait and the caliber of trout you are fishing for. If you are trolling with crankbaits I would upsize your pound test to 8lb test.

PowerBait & Live Bait

When fishing for trout using live bait or with PowerBait the best line to use is 4-8lb monofilament. Its affordable and it floats making it ideal when you want to get you bait off the bottom and into the strike zone.

Ice Fishing

If you are ice fishing for trout, I would recommend using 4-8lb test for most trout species. If you are targeting lake trout 15-20lb test is needed. The biggest determining factors when choosing the right ice fishing line strength is the caliber or size of trout you are targeting.


Trolling is a popular and effective way to catch trough. For this fishing method I like to fish with a little bit heavier line than I would if I was just casting and winding. The best pound test to use when trolling for trout is 8lb test. I would recommend using straight fluorocarbon line. It will allow your lures to get deeper and gives you the sensitivity you need to detect subtle bites.


I’ve had some incredible days fishing with jigs and tubes for trout. There is something about them that just works. The best line to use for jigs and tubes for trout is 8lb test. It’s light enough that it will allow your bait to look natural in clear water but is also strong enough for heavier wire hooks and strong hook sets.

Trout Fishing Line Q&A

Trout Fishing with 4lb vs 6lb

Perhaps the two most popular line sizes most trout anglers use is 4- & 6-pound test. I’ve have experimented with both and have learned each one has a time and place.

If you are targeting small trout in a local pond, small stream or on a lake than a lighter line like 4lb test can be a great option. You’ll be able to cast and use smaller lures and may just get a few more bites for those line shy fish.

On the other hand, if you are fishing in rivers with heavy current or are targeting larger trout than 6lb test would be the better option. This extra strength will come in handy when you are fighting larger and more aggressive fish.

Is 12lb line good for trout? In my opinion 12lb test is too big of a diameter when fishing for most trout species. This heavy of a line can be difficult to manage and throw smaller lures and baits and may result in less bites.

What is the best fishing line for rainbow trout? The best overall fishing line to use for rainbow trout is 6lb fluorocarbon. It’s a strong and sensitive line that is ideal for most any rainbow trout fishing situations.  

Are trout line shy? In my experience trout can be very line shy and lighter/clearer lines tent to work best. That’s why I would recommend using fluorocarbon fishing line. It’s pretty much invisible and will get you a lot more bites.

Does line color matter for trout? Line color can have an impact on your overall catch rate when targeting trout. This is especially true when fishing in clear water. For this reason, I always recommend using either fluorocarbon or monofilament for most trout fishing situations.

Other Trout Fishing Resources

Bottom Line

Selecting the right type and size of fishing line when targeting trout is extremely important and can impact your overall fishing success.

The right pound test of line will allow you to cast further, use certain baits and techniques effectively, and ensure you can land your prized catch.

Before you head out on your next fishing adventure make sure you have selected the right line size for your style of fishing. You’ll have a lot more success and will have a much better experience.

Aaron Warner

Aaron Warner is an avid angler with over 15 years of experience. He has participated and won fishing tournaments all over the country and enjoys fishing for bass, trout, walleye and other species.

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