Hair Extension Lengths for Wholesale Buyers: 14–30 Inches and Custom Options

The international inch is exactly 2.54 centimetres. The table converts the common reference lengths using that factor; it is not a measurement report for a pictured product. Choose either inches or centimetres as the governing order unit, and identify any rounded display value so two teams do not apply different acceptance criteria.

A historical line written as 24in / 60cm uses approximate paired references. The exact conversion of 24 inches is 60.96cm. Similarly, 22 inches converts to 55.88cm, not exactly 55cm. Preserve the source wording when describing an old order, but resolve the governing length before placing a new one.

NIST Handbook 44: length conversion reference

For a weft, agree the relevant starting point at the track and how the hair is laid out. For a tape or bonded strand, state whether the attachment is excluded from the hair-length measurement and identify the landmark used. A complete wig or topper can have different lengths in different zones, so a single extension-style measurement may not describe its intended shape.

Record the method with a simple diagram or a photograph of your own approved sample. The diagram should clarify the start and end points rather than act as a substitute for the physical sample. If the product is trimmed or layered after construction, identify whether the quoted value refers to the material before finishing or the usable finished product.

A curl or wave changes how long hair appears when relaxed. Before comparing two suppliers, agree how the pattern will be handled for the length measurement and whether the relaxed visual fall is also being reviewed. Use consistent preparation and avoid introducing an unagreed amount of tension simply to obtain the desired number.

The texture sample remains important even if the measured length agrees. Two patterns can reach the same measured length while falling differently in the intended product. Record the actual pattern, the condition under which it is assessed and any agreed washing or handling procedure. Do not treat “curly” as a standardized geometric description shared by all suppliers.

A small number of long fibres can establish a maximum observed reach without establishing full-looking ends. Buyers should therefore discuss usable length and end fullness independently. Agree how the sample will be assessed and where comparisons are made. A Double Drawn label alone does not supply that method.

This matters when comparing longer versions of an existing product. Keeping the same total weight does not automatically preserve the same distribution through the ends. If your collection extends an approved shorter item to a longer reference, review the finished sample instead of assuming that the original approval transfers unchanged.

Define an end-fullness method · Review the weight basis separately

A useful acceptance line names the product, reference length, unit, measurement landmark, preparation condition and agreed tolerance. Leave the tolerance open for confirmation if it has not been agreed; do not invent a percentage or borrow one from another supplier’s catalogue. The record should allow a different inspector to repeat the same check.

Include photographs of the method where helpful, but avoid relying on a perspective-distorted picture of a ruler as the only evidence. Retain actual readings with the sample identifier. If a result differs, first compare the methods and starting points before concluding that the product itself is different.

Custom length can be appropriate when an established reference does not meet a specific collection or construction need. Ask about the selected material, colour-processing route, texture and finished-product feasibility together. Assess the requested length alongside the selected material, shade and construction before developing a sample.

It may be unnecessary when the buyer has not yet decided the application or intended finished appearance. In that situation, a reference sample can answer the practical question with less development ambiguity. Decide what the custom length must accomplish, then ask the manufacturer to review that requirement rather than simply request the longest number.

Finland 60cm length reference · UK 55cm length reference

Explore our product specifications and linked construction references when preparing your sample request.

Prime Human Hair product specifications · NIST: exact inch-to-centimetre conversion

The end-fullness guide explains why a length label cannot describe the entire distribution of hair. The sample-evaluation checklist provides a place to record that distribution alongside the measured length. Retain both observations when approving a longer version of a previously accepted product.

End-fullness measurement methods · Sample evaluation and recorded measurements