When it comes to eyelash extension lengths, there’s a fine line between gorgeously fluttery and uncomfortably long. When I first started out, I practiced a lot to figure out the best extension lengths for each client and each lash style.

With this eyelash extension length guide, I hope to save you the hassle!

Let’s get started!

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What Are the Different Eyelash Extension Lengths?

Short Lash Extensions: 4-8 mm

These short lengths are ideal for the inner corner or very natural looks.

Medium Lash Extensions: 9-12 mm

Medium extensions are the most popular. They’re ideal for the center and outer corner of the eye, especially when clients have medium or short lashes.

Long Lash Extensions: 13-16 mm

This is the longest length I’ll use. They’re ideal for the center and outer corners on clients with longer lashes.

Very Long Lash Extensions: 17-22 mm

These extremely long extensions should only be used on clients with very long and healthy natural lashes who like a dramatic style.

Ultra-Long Lash Extensions: 23-30 mm

While some retailers sell extensions at this length, they’re a little absurd and never come in handy.

Lash Extension Length Chart

Having a handy lash extension length chart will help you remember the big difference a single millimeter can make. Print it out and you’ll be able to refer back to it as needed.

How to Choose the Best Eyelash Extension Length

You’ll usually use lashes in 3 or 4 different lengths to create your lash map. The most important factors to consider before choosing a length are:

• Natural lash length
• Desired Style
• Eye shape and structure
• Natural lash condition

Let’s take a look at each factor in detail.

1- Natural Lash Length

The ideal lash length for your client will never extend more than 2 mm past their natural lashes.

The natural lash line has its own length variation, so you can measure the extensions against the natural lashes as you work. You’ll often discover you usually need to go shorter near the inner corner, and that you can go longer near the center and outer portion of the lash line.

I also take distance from the eyelid into account. That’s because the extension is not attached directly at the base of the natural lash. We leave a 1 mm gap so that the extension never touches the skin.

That means that in practice, I choose extensions that are 1 mm longer than the natural lash length. For example, if a client has 10 mm long natural lashes, I want to extend them to 12 mm. As such, I’ll choose an 11 mm long extension.

To see measuring in action, check out this wonderful video from Eyelash Excellence:

Some lash technicians stick by a “3 mm” or “4 mm” rule¹, but over the years, I’ve learned that it can do more harm than good. With my 2 mm rule, many of my clients have been able to keep their extensions on for many years without any lash damage or needing breaks.

2- Lash Style

• Natural: This style features shorter extensions that follow your client’s natural lash length closely.
• Cat-eye: With this style, start with the shortest lashes near the inner corner and gradually increase length towards the outer corner.
• Dolly eye: With this style, the lashes are longest in the center and shorter at the inner and outer corners. 
• Natural sweep: Shorter extensions are used for the inner corners of the eyes while longer lengths are added throughout the lash line.

3- Eye Shape and Structure

• Hooded/monolids: You run the risk of long, curly lashes poking the eyelid when the eyes are hooded. Opt for a shorter style with some dolly eye length in the center of the lash line.
• Deep-set eyes: Longer lengths should be used for clients with eyes that are deep inside the eye cavity in order to compensate.
• Protruding eyes: Shorter lengths should be used for clients with eyes that are slightly protruding.
• Shallow-set eyes: with this eye shape, you can use either long or short lengths. Other factors will dictate the length you should choose.

For even more lash mapping tips based on eye shapes, check out my guide on eyelash extension styles for the 6 main eye shapes.

4- Lash Condition

If your client’s lashes are quite brittle, err on the side of shorter, lighter lashes. The healthier the natural lashes, the longer you can go, but I still urge you to stick to the 2 mm rule.

I’ve used this rule of thumb with great success and I’m sure you will too. By following the 2 mm rule, you can achieve a beautiful look without the risk of overloading the natural lashes.

FAQ

References

1. Lash Affair (2017), Tips To Choosing the Right Lash Extension Length. Retrieved from https://lashaffair.com/blogs/lash-artist-blog/tips-to-choosing-the-right-length [Accessed November 24, 2022]