An American woman’s size 4 to 5 corresponds to a size 27 in jeans. The waist measurement is 27. The sizing of jeans varies greatly from nation to nation and occasionally by brand or design.
In the US, there are two jean sizing systems. Designer or high-end manufacturers frequently adopt a sizing system based on waist measurements. The smallest portion of the waist should be measured in order to establish the correct jean size.
A size 27 corresponds to a size 9 in New Zealand, Australia, and the UK. It is a size 40/42 in Italy. It is a size 36/38 in France. It is a size 7/9 in Japan. A size 27 in Denmark falls between a size 32 and a size 34.