How old does a girl have to be wear bikini in public?

There are different laws and regulations regarding the age at which a girl can wear a bikini in public, and these can vary depending on the jurisdiction. In most cases, the minimum age for wearing a bikini in public is determined by the local laws on public decency and indecency. Generally, the minimum age is between 13 and 16 years old. However, some jurisdictions may have stricter or looser regulations. It's important to consult the local laws and regulations to determine the exact minimum age for wearing a bikini in public in a specific area.