The Square Knot, also known as a Reef Knot, is a simple knot that’s used to join two lengths of rope together. It’s a crucial knot that all sailors should learn. If you’re not familiar with this one, we’ve got all you need to know about it right here: a little bit of background information and a short guide about how to tie a Square Knot.

Curiously, the Square Knot is actually two half knots rather than a single knot. It’s a binding knot that can be used for a wide range of purposes. It can be used to tie down a sail cover, tie your shoelaces, for tying the string on a gift, or as one of the key knots used for macrame.

It’s worth noting that all of those example uses are for times when safety isn’t important. If you need a knot to carry your weight when climbing a mountain, or for lifting heavy cargo over your head, then the square knot is not the right knot for the job.

For joining, it’s great. For safety-critical purposes, it’s not. However, it’s such an incredibly practical knot that teaches some basic knot-making fundamentals, it’s essential that all sailors learn it. If you want to learn how to perform a Half Knot and Half Hitch, then learning how to tie a square knot will put you on the right path. So, without further ado, here’s how it’s done.

How To Tie A Square Knot

Grab a length of rope and learn how to tie a Reef Knot, more commonly known as: the Square Knot!

Step 1: Using two lengths of rope, lay them side by side and cross one over the other to form a half knot.

Step 2: Cross the two ends over a second time.

Step 3: Pull the ends tightly together.

Step 4: Tighten the knot as much as necessary and enjoy your completed Square Knot.

Other Things To Consider

Before you rush out and start securing everything you own with your newly learned Square Knot, take a few moments to learn a little more about the knot, its uses, and its shortcomings. It has quite a few shortcomings and it’s best to know them before putting your life in the hands of a sub-standard knot!

Watch Out For The Granny Knot

It’s very easy for beginners to accidentally tie a Granny Knot instead of a Square Knot. A Granny Knot looks similar to the Reef Knot but it’s not the same. It’s a binding knot that can be used to secure a rope to an object, but like the Square Knot, it’s not a trustworthy knot. In fact, the Granny Knot is even more insecure than a Square Knot. It’s important you don’t mix the two up for this very reason!


Square Knots can easily unravel. If you’re tempted to try and reinforce a Square Knot by adding a number of extra Square Knots to secure it, don’t! A stack of Square Knots can come undone just as easily as a single knot. That’s why you should never use this knot when dealing with critical loads or for safety purposes. Here’s a quote from the Ashley Book Of Knots about the Square Knot’s untrustworthiness: “There have probably been more lives lost as a result of using a Square Knot as a bend (to tie two ropes together) than from the failure of any other half dozen knots combined.

Similar Knots

Aside from the aforementioned Granny Knot, similar knots to the Reef Knot include the Double Throw Knot, sometimes known as the Surgical Knot. This knot is often used during surgery, usually compounded with other ties for added strength.

The Thief Knot is also similar to the Reef Knot. Though it looks the same it has some differences. Sailors would use this knot to secure their belongings when out on a voyage, or so it is said.

Square Knots: In Summary

Though the Square Knot isn’t the most secure or trustworthy knot you can learn, it’s still an important knot to know. It’s quick to execute and has a wide range of uses. As long as it’s not a mission-critical purpose, knowing how to tie a Square Knot will certainly come in handy on your next voyage.