How Are Hair Extensions Measured? A Guide to Choosing the Right Length

One of the most common questions we receive is:

"Why does my curly or wavy hair look shorter than the length I ordered?"

The answer is simple: all hair extensions are measured when fully stretched, not when worn in their natural texture.

Understanding how hair extensions are measured will help you choose the right length and avoid disappointment when purchasing bundles, clip-ins, frontals, closures, or custom units.

How Are Hair Extensions Measured?

Hair extensions are measured from the top of the weft (or attachment point) to the very ends of the hair.

For straight hair, the measurement is taken with the hair lying flat.

For wavy, curly, and coily textures, the hair is gently stretched straight before measuring.

This means that a 20-inch bundle is always 20 inches long when fully extended, regardless of its texture.

Why Does Curly Hair Look Shorter?

Curly and textured hair naturally shrinks due to its curl pattern.

The tighter the curl pattern, the greater the shrinkage.

As a general guide:

• Straight hair appears close to its advertised length.

• Body wave hair may appear 1–2 inches shorter when worn naturally.

• Deep wave hair may appear 2–4 inches shorter.

• Curly and coily textures can appear several inches shorter depending on the curl pattern.

This does not mean the hair is shorter than advertised—it simply means the curls are taking up part of the length.

Choosing the Right Length for Your Desired Look

When selecting your bundles or wig, consider the finished look you want rather than focusing solely on the number of inches.

For example:

• A 18-inch straight style will appear significantly longer than a 18-inch curly style.

• Clients wanting long, voluminous curly hair often choose a longer length tlike 20" and above. 

• If you're unsure, consult your stylist before ordering.