What the figure eight knot does and when to use it
The figure eight knot is a stopper knot that prevents line from slipping through a guide, a reel, or a knot you've already tied. You tie it at the end of your line or anywhere you need to lock something in place. It's thicker and more reliable than an overhand knot, which is why it's the standard choice when you're rigging a rod and you want to be certain nothing unravels under load.
Anglers use it most often as a backing knot — tied at the very end of your backing line so that if you run out of fly line in a fight, the backing won't slip through the reel. It also works as a stopper knot on a leader when you're using a bobber or float, or anywhere else you need a knot that won't pass through hardware. The figure eight is stronger than it looks and holds reliably in both monofilament and braided line.
Key Takeaways
- The figure eight knot creates a bulge in your line that stops it from slipping through guides, reels, or other knots.
- It's tied by making a loop, wrapping the line around itself, and threading the end back through the loop — a shape that resembles the number 8.
- The knot works in monofilament, fluorocarbon, and braided line, though braided line requires slightly tighter cinching.
- Trim the tag end close after tightening to keep it from catching on guides or snagging weeds.
How to tie the figure eight knot step by step
Start with the line in your hand, about 6 inches from the end. Make a loop by crossing the tag end (the short end you're working with) over the main line. The loop should sit loosely in your palm.
Wrap the tag end around the main line, going behind it and then forward again. You're creating the shape of a figure 8 — the first loop is at the top, and you're building the second loop below it. Thread the tag end back through the top loop, pulling it toward you. Tighten by holding the main line steady and pulling the tag end with steady pressure until the knot cinches down. The finished knot should look like the number 8 lying on its side.
Trim the tag end with scissors or a knife, leaving about an eighth of an inch. A tag end that's too long can catch on rod guides or snag vegetation in the water. A tag end that's too short may slip, so leave a small amount.
Why the figure eight holds better than other stopper knots
The overhand knot — the simplest knot most people know — can slip under heavy load, especially in slippery materials like braided line. The figure eight creates more friction because it wraps around itself twice instead of once. That extra wrap means the knot grips the line more firmly and resists sliding.
The figure eight also distributes stress more evenly across the knot itself rather than concentrating it at a single point. This means it's less likely to weaken the line or fail suddenly. In a long fight with a heavy fish, that difference matters. The knot has been standard in sailing and climbing for decades for the same reason — it simply holds.
Using the figure eight in different line types
In monofilament and fluorocarbon, the figure eight cinches down smoothly and holds without fuss. These lines have enough grip that the knot tightens evenly and stays put. Pull the tag end firmly but not so hard that you risk breaking the line, and the knot will seat properly.
Braided line is slicker and requires a firmer hand. Cinch the knot tighter than you would with monofilament, and consider making two passes through the top loop instead of one if you're using very thin braid. Some anglers wet the knot with saliva or water before tightening to help it seat, though this is optional. The knot works in braid, but it demands attention to detail.
Common mistakes and how to avoid them
The most common error is leaving the tag end too long. A long tag end catches on guides during the cast and can cause the line to fray or tangle. Trim it close — an eighth of an inch is enough to prevent slipping but short enough to stay out of the way.
Another mistake is not tightening the knot firmly enough. A loose figure eight will slip under load. Pull the tag end with steady, deliberate pressure until you feel the knot grip. It should be snug enough that you can't slide it along the line by hand.
Some anglers also tie the knot too far from the end of the line, leaving a long stretch of line beyond the knot. This defeats the purpose — the knot needs to be at or very near the end so it can catch on whatever you're trying to stop. Tie it within an inch of the end.
When to replace a figure eight knot
Inspect your figure eight knot before each fishing trip. If the line shows signs of fraying, discoloration, or damage near the knot, retie it. A knot that's been wet and dried repeatedly can weaken, especially in monofilament exposed to sun.
If you've had a hard fight or felt the line slip at any point, cut off the old knot and tie a fresh one. The line near a knot that's been under stress may be compromised even if the knot itself still looks intact. Replacing it takes two minutes and removes doubt.
Frequently Asked Questions
Can I use a figure eight knot on the end of a fly line?
Yes, but most fly anglers tie it on the backing line instead, since the fly line itself is already thick and won't slip through a reel. If you do tie a figure eight on fly line, use a lighter touch when cinching — fly line is delicate and over-tightening can damage it.
What's the difference between a figure eight and a double overhand knot?
A double overhand knot wraps around twice but doesn't create the same shape or grip. The figure eight is stronger and more reliable under load. If you know how to tie a figure eight, use it instead.
Does the figure eight knot weaken the line?
All knots reduce line strength slightly because they create a bend that concentrates stress. The figure eight is one of the least damaging stopper knots, but it will still reduce strength by roughly 10 to 15 percent. This is why you tie it at the end of the line where it's least likely to be the breaking point.
Can I tie a figure eight knot in the middle of my line?
Yes. Some anglers tie a figure eight in the middle of a leader to create a stopping point for a bobber or float. The knot works the same way — it just sits in the middle instead of at the end. Make sure it's tight enough that the bobber can't slide past it.
How do I know if my figure eight knot is tight enough?
Try to slide the knot along the line with your fingers. If it doesn't budge, it's tight enough. If it moves even slightly, pull the tag end again until it stops. A knot that slides under hand pressure will slip under the stress of a fighting fish.