Every returned item costs you shipping twice, inspection and repackaging — sometimes the item itself. In apparel, most returns come down to size.
Why "S / M / L" is not enough
There is no shared standard between suppliers. An M from one may equal an L from another. A customer who cannot find real numbers guesses, and guessing means returns.
What a size chart must contain
- Measurements in centimetres, not just letters: chest, waist, length, shoulder.
- How to measure — customers do not know where the chest is measured from.
- The size worn by the model in the photos.
- A note on the fabric: does it stretch? does it shrink after washing?
Put it where the decision happens
The size chart link belongs beside the size selector, not on a separate page in the footer. Customers will not go looking for it.
Measure the effect
Record your return rate before adding the chart and a month after. If it does not fall, the problem is the product or the photography rather than sizing — also worth knowing.