In New Hampshire, the age of consent is 16 years old for heterosexual conduct. For homosexual conduct, the age of consent is 18. This makes New Hampshire one of the few states explicitly permitting homosexual conduct by creating an age of consent for it.

Unlike most other states, New Hampshire has a single age of consent. In the majority of other states, there is an allowance for minors who are under the age of consent, but close to the same age. New Hampshire has no such allowance.

So, in New Hampshire, a person who is 16 years old cannot have sex with a person who is 15, even if they are going to turn 16 in a day.