Donor Hair Length & Weight: What the Numbers Mean

Every listing shows two numbers — length and weight. Here is how to read them for what they really are: the specs of raw single-donor hair you will turn into extensions.

How we measure length: in the natural pattern, unstretched

Hairlenza measures every bundle as the hair naturally lies: curls stay curled, waves stay waved, nothing is pulled straight. A curly bundle listed at 45 cm looks 45 cm — the number matches the photos and matches what ends up on the head. We consider this the only honest way to state textured length. Be careful comparing across sellers: many measure stretched, so their "60 cm curly" may visually be shorter than our 50 cm. When comparing listings, always find out the measurement method first — and if you need a stretched figure of our specific piece for your calculations, ask: we will measure it personally on request.

What the grams mean for extension making

Weight is your material budget. 80–110 g — partial volume, face-framing, or full length for fine hair. 110–150 g — the workhorse range covering most standard full installs. 150–190 g — dense, dramatic results, or a standard install plus reserve strands for future touch-ups. 190 g+ — maximum density projects and thick natural hair. These are orientation points, not prescriptions: the true requirement depends on the client's own density, head size, and whether the format is K-tips or wefts — a stylist calculates it exactly. When torn between two bundles, the heavier wins: leftover single-donor hair is future repair material, while missing grams cannot be matched later from another donor.

Length and weight work together

The same 140 g reads differently at different lengths: at 45 cm it is a dense bundle; at 70 cm the same mass distributes further and the result is airier toward the ends. That is physics, not quality. Never compare listings by one number: read the pair. Moderate length with solid weight almost always makes a richer install than maximum length with low weight.

Inches or centimeters

US listings favor inches, European — centimeters; 1 inch = 2.54 cm. Our catalog shows both and lets you switch units: 45 cm ≈ 17.5", 50 cm ≈ 19.5", 55 cm ≈ 21.5", 60 cm ≈ 23.5". Whichever unit you use, remember it is the in-curl figure.

The honest comparison habit

Line bundles up as pairs — "45 cm / 155 g curly" against "55 cm / 120 g curly" — and picture the trade: the first builds denser, the second longer and lighter. With one-of-a-kind hair there is no restocking the piece you passed on, so decide by the pair of numbers plus daylight photos, and confirm the required grams with your stylist before the piece is gone.

Quick answers

How does Hairlenza measure hair length?
In the natural texture, unstretched: curls are not pulled straight. A 45 cm curly bundle visually is 45 cm. A stretched measurement of a specific piece is available on personal request.
Is 120 grams enough for a full install?
For many clients yes — 110–150 g covers most standard full installs. Fine hair may need less, dense results more. Have your stylist calculate from your own density before buying.
Why does your 50 cm curly look longer than another seller's 60 cm?
Different measurement methods. Many sellers measure stretched, which inflates textured lengths. We measure in the natural curl, so our number matches what you see and wear.
Should I choose by length or by weight?
Read them as a pair. Weight is the material budget (what can be made); length is where it ends. Moderate length with solid weight usually beats maximum length with low weight.