Everything You Need to Know About Eyelash Extension Size

For a lash artist, regardless of whether you are a master or a newbie, the most important work is in choosing the correct length, curl, and thickness of lashes for each client.  To create satisfied looks without causing any damage to the client’s natural lash, it’s very crucial to know clearly about the specification of lash size and the most appropriate size for every client. 

This is the eyelash extension curl chart and guidelines and here are different eyelash extension curls and sizes. Let’s look through it one by one.


  • J curl is the softest and most natural curl. It lasts longer, used for adding volume or length, but not used often.
  • B curl is more curl than J with a better retention. It is used if the natural lash is straight. It is mostly used for the inner corner.
  • C Curl is the most natural-looking and popular curl. It is recommended for clients who want their eyes open. It matches every eye shape and it has a good retention, but not good as J and B curl.
  • D curl is a more dramatic curl, even though its retention may not be as good as J B or C. It is perfect for clients with downturned eyes. It is not for deep-set eyes.
  • L curl, has a shape like “L”, with a flat and straight base and it provides a dramatic lift angle. It offers a super dramatic effect and it is perfect for clients with deep-set hooded eyes.
  • Besides those listed above, there are CC and DD. These two offer super glamorous and add lift. It has a poor retention due to the fact that the bonding area between natural lash and extension is small.  
  • Among all the curls, C and D are the most popular. C is for obtaining the most natural-look, while D is for a more dramatic look.

Note that, different clients have different eye shapes. Usually, the main shapes include Almond eye, close-set eye, deep-set eye, downturned eyes, hooded eyes, monolid eyes, round eyes. Only the right curl will work out the appropriate desired looks and enhance the beauty of your client. So, the first step is to check for the eye shape, and determine curls that will match the client’s unique characteristics. Never choose D curl for clients with straight lashes. This is the basic of lash artwork. Each curl creates a unique effect and is recommended based on the look you’re going and how your natural lashes are shaped.


0.03, 0.05, and 0.07mm

They are super light, create volume fans, and mega volume lashes. These are good for volume eyelash extensions which are more complicated than classic in applying small fans to natural lashes without adding extra weight. Making fans require high application techniques and time to practice, a longer application time than classic, and a higher price volume also. 

  • 0.10, 0.15, and 0.18mm

They help to create a natural look. The idea is to make a classic extension, where only a single eyelash extension is applied to an individual. They add length and curl to lots of natural lashes.

  • 0.20, 0.25mm

They help to create a natural mascara and glamorous look, but it’s definitely heavy for many natural lashes. It can cause natural lash to fall out quickly. It is usually not suggested unless the client’s natural lash is strong enough.

Choose the right diameter and avoid being too long or too thick in order to keep the natural lashes well.

Length in 5-20mm

Short: 5mm-7mm / Medium: 8mm-12mm / Long: 13mm-15mm / Extra long: 16-20mm. Of all these, 12mm is most popular length. It can mix with different lengths to get a natural-look or dramatic look. Length of lash extensions depends on the length of the natural lash. It is important to analyze natural lashes carefully.  

Do not use too long or too heavy lashes for a client with short lashes. It’s better to choose a length that is 2-3mm longer than the natural lashes. If your client’s natural lashes are 10mm long and 0.10 mm thick, never apply a 0.25mm diameter or 18mm, the extra length will not last and they will be too heavy for natural lashes to support.

For the majority, 8-15mm is most often used. 16-20mm is extra-long and it only suits those who have strong and long natural lashes. 

Never use same length.

Too long extension will damage natural lashes.

How to choose size for your client?

Now that you have should have a better understanding of lash size. When a client comes to your salon, have a discussion before application. She may want a particular look. Whether they prefer length or fullness, a drastic, fuller, thicker looks, understand the client’s request and try to see if it’s workable. Afterwards, inspect the client’s unique eye shape and natural lash length. A client with short and rare lashes who prefers a fuller look must use short length in extensions. Too-long lashes will lead to an increase in weight. Most of the time, what the client wants is not what will fit them in the long run as the length and curl may not match their eye shapes.

Give your professional advice and let them know that too long lashes will cause too much weight on natural lashes, the longer, the more risk of breaking the natural lashes. Giving your professional advice is part of your service. You must consider the client’s personal lifestyle when creating a look. It’s better to record the map style on your client notes so that you can emulate the same lash design for clients with similar eye and lash. Here is how to do choose the right size:

  • Keep in mind the different lash types and the factors that is key for lash extensions.
  • Understand the client’s request and their lash characteristics.
  • Determine the right curl according to their eye shape.
  • Determine the right thickness for desired looks.
  • Choose a length which is 2-3mm longer than natural lashes, and map length before application.
  • Finally, fit the client’s needs and wants.

Each lash extension is customizable. Remember, everyone’s eyes are different and this means that lashes will vary in size also. Only the right choice will enhance the client’s beauty. The ultimate goal is to match everything to the client’s natural lashes and create the beauty they desire. 

Leave a Comment

Your email address will not be published. Required fields are marked *