Curling Iron Size Guide – Size & Curl Patterns

| Last Updated: January 1, 2021

Whether you’re looking for big, bouncy, glamor curls or loose beach waves, a curling iron can be the diverse tool to use to craft these looks. When trying to achieve these styles, the size of your curling iron will be a major influence on the desired outcome. By relating the size of the curling iron to your relative weight and length of your hair, you can work out the ideal curling iron to fit what you’re looking for, creating the ideal curly style for you.

Sizes Curling Irons Come In

Curling irons are measured by circumference of the barrel. The barrel is the metal part you wrap your hair around, that heats up to create the curl. The size of the curling iron refers to the measurement taken all the way around this barrel.

There are a plethora of sizes of curling irons that range from 3/8-inch to 2-inch in circumference. The sizes most often found for easy purchase are 3/8-inch, 5/8-inch, ¾-inch, 1-inch, 1.25-inch, 1.5-inch, 1.75-inch, and 2-inch. Sometimes you can find barrels that are 0.5 inches, but it is far more common to find 3/8-inch and 5/8-inch barrels.

The Curls You Get With Each Size  

The barrel size directly relates to the achievable curly style. This is also related to your hair length. For smaller size barrels, the curl will be tighter. However, for people will long hair, the weight of this hair will mean that a tight curl of this nature won’t last as long. Equally, while larger barrels make looser, more bouncy curls, they are often too big to create any curl for someone with short hair, instead just providing volume.

When using a 3/8-inch barrel, the finished product will be a very tight, springy curl. You can either use it for super-kinky ringlets or run your fingers through your hair for full volume. This size barrel is best for short-to-medium hair. While it will give a tight curl for long hair, it is very hard to get this curl to hold for long.

A 5/8-inch barrel is more suitable for people with long hair that want tight curls. While this size barrel is great for creating ringlets for short hair or for tidying up naturally curly hair, it can also create the tight look for long hair without dropping out too quickly.

A ¾-inch barrel creates the look of more structured curls. For medium or long hair, this is the size usually used for creating “up dos.” For shorter bobs, this will give a structured look but appear looser. If you comb the curls through, this size barrel is ideal for giving a textured feel.

A 1-inch barrel is the perfect size for the more natural-looking curl, especially for short or medium hair. With this barrel, the curls fall in a less-structured manner. This is the barrel to create beachy looks for short and medium hair.

A 1.25-inch barrel creates an even looser wave. For short hair, this will create a very light wave, whereas it creates flowing curls for medium and long hair. For long hair, you can brush through with your fingers to create a natural-looking texture.

If you’re looking for large, voluminous curls, a 1.5-inch barrel will create the bouncy glamor curls often coveted from magazine covers. This barrel suits medium to long hair.

A 2-inch barrel will create full-bodied hair. The ringlets are loose and you can create an even-more-casual tousled look if you run your fingers through your hair after curling.  This barrel works best on longer hair.


Choosing the right curling iron in relation to your hair will help you to create the style you’re looking for. While you can play with the style of the curl, the barrel size is integral to whether you’ll create the fierce, springy full head of curls or that casual tousled feel. Try to remember that the weight of your hair will affect how long the curl will hold and that larger curls last longer, especially for heavy, long hair.

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Hi I'm Emilia! I like to think of myself as the "crash-test-dummy" of the hair world. Whether that means testing out the newest curling iron or going with fresh hair styles. I like to mix it up. I share my thoughts on Caffe Hair based on my first hand experience!

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