
What Size Line For Trout Fishing? Detailed Chart
Today, we’ll discuss the best line size for trout fishing and how to determine which line is ideal for it.

The behavior of each fish species varies when it comes to line, bait, and fishing style, so it’s necessary that your fishing line matches the specific behavior of trout for successful fishing.
Check our recommendations on Best Fishing Lines for Trout
Basics of Fishing Line Strength and Size
A fishing line is rated by its “test,” which measures breaking strength and how much weight it can handle before breaking. This knot strength rating pound test is given in pounds (lb). For trout fishing, the line test you choose affects your ability to catch fish and how your bait or lure behaves in the water.
Line Size for Trout Fishing
Line Type | Best For | Use Cases | Advantages | Disadvantages | Recommended Brands |
---|---|---|---|---|---|
Light (2-4 lb) | Clear water, cautious trout | Small lures, bobbers | Low visibility, delicate presentation | Breaks with larger fish or snags | Berkley Trilene XL |
Medium (6-8 lb) | Larger trout, snags | Trolling, heavier lures | Good balance of strength and manageability | More visible in clear water | P-Line Fluorocarbon |
Heavy (10-12 lb) | Large trout, deep water | Lake fishing, heavy cover | Strong and durable for rough conditions | Highly visible, reduces subtlety | PowerPro Braided Line |
Recommended Line Sizes for Different Trout Fishing Scenarios
Light Lines (2-4 lb test)
Best for Clearwater and cautious trout.
Ideal for casting spinners and small lures and using bobbers.
Light lines are less visible to trout, which can increase your chances of getting a catch trout bite. They also allow for a more natural presentation and delicate presentation, essential in clear water.
But, they can break more easily if you hook a larger fish or get caught if there are many snags in the water.
Recommended Brands: Berkley Trilene XL is our go-to for its excellent castability and durability. (Check On Amazon)
Medium Lines (6-8 lb test)
Best for: Larger trout or areas with potential snags.
Ideal for: Trolling and using heavier lures.
It provides a floating line with a good balance between strength and visibility. Medium lines are strong enough to handle bigger fish and more challenging environments while still being manageable.
But, it’s slightly more visible on the water column with heavier lines than the water column with lighter lines, which can be a drawback in very clear water.
Recommended Brands: We recommend P-Line Fluorocarbon for its sensitivity to light and low visibility. (Check On Amazon)
Heavy Lines (10-12 lb test and above)
Best for Targeting large trout or fish caught in strong currents or deep waters.
Use cases: Lake trout fishing, heavy cover areas.
Heavy lines are very strong and durable and can handle large fish and rough conditions. Great for deep water and heavy-cover fishing.
But, Heavier lines are more visible and can reduce the subtlety of your presentation.
Recommended Brands: PowerPro Braided Line combined with a fluorocarbon leader works wonders for us. (Check On Amazon)
Check our recommendations on Best Trout Lures – Top 10 Picks Reviewed
Line Types and Their Impact on Size and Weight
Choosing the right type of fishing line for trout is just as important as choosing the right size. Here are the three main types of fishing lines and their features:
Fluorocarbon
Fluorocarbon is known for its low visibility, sensitivity, and abrasion resistance. For clear water conditions where trout are line-shy, a 4-8 lb test is ideal. Its nearly invisible quality underwater makes it perfect for cautious fish, and its high sensitivity allows you to detect even the slightest bites.
Monofilament Fishing Line
Monofilament is stretchy, visible, and manageable. For general trout fishing, we recommend using a 2-6 lb test. It’s versatile and easy to handle, making it suitable for both beginners and experienced anglers. The stretch in monofilament acts as a shock absorber, helping to prevent breakage when a trout aggressively takes the bait.
You might want to read: Monofilament Vs Fluorocarbon – Which One’s Best For You?
Braided Line
Braided lines are highly durable, have no stretch, and offer great strength. A 6-10 lb test is recommended for deep water or fishing in heavy cover. To increase invisibility, pair it with a fluorocarbon leader. Braided lines are incredibly strong and durable, making them ideal when you need to feel every nibble and handle rough fishing conditions.
You should also read these articles:
Braided Line Vs. Monofilament Line – Which One’s For You?
10lb Braid Vs 10lb Mono – Which One’s Stronger?
Environmental Considerations
Water Clarity
Use lighter lines (2-4 lb test) and low-visibility options like fluorocarbon. For murky water, medium to heavy lines (6-12 lb test) are suitable. Visibility is less of a concern, so you can use stronger lines.
Fishing Location
For Streams and Small Rivers, use light to medium lines, typically in the 2-6 lb test range. These environments often require more delicate presentations to avoid spooking the fish.
In Lakes and Deep Waters, medium to heavy lines (6-12 lb test) are recommended. These areas usually have larger fish and more cover, so a stronger line is necessary to handle the conditions effectively.
Tips for Choosing the Right Line Size
- Match Your Rod and Reel: Ensure your line size is compatible with your rod and reel setup. This helps in maintaining balance and performance.
- Balance Strength and Invisibility: Choose a line that provides the right strength for your target fish while being as invisible as possible.
- Regular Maintenance: Check your line regularly for wear and tear. Replace it as needed to avoid unexpected breaks.
Also read our guide on What Size Reel For Trout Fishing?
Various Fishing Scenarios and Tips
Clear Water Streams
In clear water streams, trout can be extremely cautious. Using a light line (2-4 lb test) with a small lure or spinner can be very effective. The light line reduces visibility, making it less likely for the wary trout to to detect it. Additionally, using a low-visibility line like a fluorocarbon line can further enhance your chances of a catch. In these scenarios, a delicate presentation is crucial. Make sure your casts are accurate and gentle to avoid spooking the fish.
Expert Tip: When fishing in clear streams, always approach the water slowly and try to keep a low profile to avoid being seen by the trout. Wear neutral-colored clothing to blend in with your surroundings.
You might want to read: Water Clarity Lure Color Chart
Murky Water Lakes
In murky water conditions, visibility is not as much of a concern, allowing you to use a leader with a heavier line or medium to heavy braided fishing line (6-12 lb test). These lines provide the strength needed to handle larger trout that might be hiding in deeper waters or around heavy cover. Using a line visibility leader with a durable line like braided line paired with a line twist a fluorocarbon leader can offer the best of both worlds – strength and low visibility.
Expert Tip: In murky waters, using brightly colored lures can help attract the attention of trout. Opt for lures that create vibrations more light or noise to make them more noticeable.
Also, check: Do Jerkbaits Work in Muddy Water? Tips and Techniques for Success
Large Rivers
Large rivers can present a variety of challenges, from strong currents to larger fish. In these environments, a medium line (6-8 lb test) is typically ideal. It offers a good balance of strength and manageability. Trolling the river with heavier lures can be effective in these conditions, allowing you to cover more water and target fish at different depths.
Expert Tip: When trolling rainbow trout in large rivers, vary your speed and depth to find where the brown trout are feeding. Using a depth finder can help you locate schools of fish.
Deep Water Lakes
A heavy line (10-12 lb test) is necessary for deep water lakes where larger trout are often found. These lines can handle the strong pulls of big fish and the potential snags in deeper waters. Braided lines are particularly useful in these scenarios due to their strength and sensitivity. Pairing a braided line with a fluorocarbon leader ensures the line remains strong while reducing visibility.
Expert Tip: When you fly fishing in deep waters, use a fish finder to locate fish at the same diameter and depth at which the trout are swimming. Drop your own fly, rod, or bait just above this fish for depth and fly down to increase your chances of a catch.
Maintenance and Care of Fishing Lines For Longer Lifespan
Regular maintenance of your fishing line is essential to ensure its longevity and performance. Here are some tips to keep your fishing line in top condition:
- Check for Abrasions: Before each fishing trip, run your fingers along the length of the line to feel for any nicks or abrasions. These can weaken the line and lead to breaks. If you find any damaged sections, cut them off and re-tie your lure or hook.
- Avoid Overexposure to Sunlight: Prolonged exposure to UV rays can degrade fishing lines, especially monofilament lines. Store your fishing line in a cool, dark place when not in use to extend its life.
- Proper Spooling: Ensure your line is spooled onto your reel correctly to prevent line twists and tangles. Overfilling or underfilling your reel can lead to problems when casting or retrieving.
- Regular Cleaning: After each fishing trip, rinse your line with fresh water to remove any dirt, salt, or debris that could weaken it over time. This is especially important if you’ve been fishing in saltwater.
- Replace Regularly: Even with the best care, fishing lines will eventually wear out. Replace your line regularly to ensure it remains strong and reliable.
Must Read: How Long Does Fishing Line Last? & What Weakens Fishing Line?