Hair extension length guide.
See where 18, 20, 22 and 24 inch extensions fall, and how to choose a length that blends with your own hair.
See where it falls.
Choose a length to see roughly where it sits on someone around 5′5″.
18″ falls across the shoulder blades.
Enough length to see a difference, still easy to style and wash.
Shop 18″ extensions20″ falls at the bra strap.
The length most people choose for a first set. Long, but believable.
Shop 20″ extensions22″ falls just below the bra strap.
Noticeable length with room for soft waves to keep their shape.
Shop 22″ extensions24″ falls at mid-back.
Statement length. Best on hair that is at least collarbone length.
Shop 24″ extensionsHow extensions are measured
Extensions are measured from the weft, or the top of the tape, to the tips. Where they fall depends on your height and where they are fitted, so our guide is based on someone around 5′5″ with extensions fitted at the usual height.
Where each length falls
- 18 inches (46 cm): across the shoulder blades. Enough length to see a difference, still easy to style and wash.
- 20 inches (51 cm): at the bra strap. The length most people choose for a first set: long, but believable.
- 22 inches (56 cm): just below the bra strap. Noticeable length, with room for soft waves to keep their shape.
- 24 inches (61 cm): at mid-back. Statement length, best on hair that is at least collarbone length.
Choosing a length for your hair
Extensions blend most naturally when your own hair is long enough to cover the rows and soften the point where it ends. For 22 and 24 inches, your hair should ideally be collarbone length or longer. If your hair is shorter, 18 or 20 inches will look more natural, and your stylist can blend the ends.
Length and fullness
The same weight of hair looks thinner at 24 inches than at 18, because it is spread over a longer length. Most people need 100–150g for natural fullness and 150–200g for a fuller finish; choose the higher end for longer lengths.
Length questions
What length of hair extensions should I choose?
Extensions are measured from the weft to the tips. On someone around 5′5″, 18 inches falls across the shoulder blades, 20 inches at the bra strap, 22 inches just below it and 24 inches at mid-back. For 22 inches and longer, your own hair should reach at least your collarbone so the blend looks natural.
How many packs of hair extensions do I need?
Most people need 100–150g for natural fullness and 150–200g for a fuller finish. Fine hair sits at the lower end, and longer lengths need a little more to stay full at the ends. Tape-ins and genius wefts come in 50g packs and volume genius wefts in 100g wefts, each with a calculator on its product page. Clip-ins come as a full-head set.