The age of consent is the age at which a person can legally agree to sexual activity. That definition is simple. Almost everything that follows from it is not, because the United States does not have one age of consent — it has fifty-one separate answers.
There is no national figure
Congress has never set a general age of consent. Criminal law of this kind is overwhelmingly a state matter, and the federal statutes that touch on the subject apply in specific circumstances — conduct on federal land, conduct crossing state or national borders, offenses involving interstate communications — rather than displacing state law.
What remains is 16, 17 or 18 depending on where you are:
- 16 in 31 states, the most common threshold
- 17 in 8 states
- 18 in 11 states
The age of consent map shows where each falls. The variation is not a graduated national judgement about maturity; it is the residue of fifty-one independent legislative histories. Many states carried a threshold of 16 forward from reforms enacted decades ago and never revisited it. Others raised it during later waves of child-protection legislation.
The number alone rarely answers the question
Most states do not operate a simple legal-or-illegal switch at the age of consent. They define bands, with conduct involving younger children treated far more seriously, and a graded structure of offenses above that. A state whose age of consent is 16 may still impose severe penalties for conduct involving a 13-year-old.
Layered on top are close-in-age provisions, which narrow the statute's reach where two people are near in age. These are commonly called Romeo and Juliet laws, and they vary enormously — some eliminate liability, some only reduce the offense grade, some only remove the registration requirement. Eight states have none at all.
Consent is not the deciding factor
These statutes exist precisely because the law treats a person below the threshold as unable to give legally effective consent to the conduct in question. Willingness does not change the analysis. That is why they are frequently described as strict liability offenses: the prosecution generally does not need to prove intent to commit an offense or knowledge of the other person's age.
A related point catches people out constantly. In many states, a reasonable mistake about age is not a defense — even where the belief was genuine, and even where the younger person actively misrepresented their age or produced identification.
What the age of consent does not govern
Two things sit outside it entirely, and both are commonly assumed to be covered.
Images and messaging. Governed by separate statutes that use 18 throughout, including federal law, and generally without close-in-age relief. A 16-year-old in a state where the age of consent is 16 can be in a lawful relationship while photographs exchanged within it fall under federal statutes.
Authority relationships. Nearly every state raises the threshold, or removes close-in-age protection, where one party is a teacher, coach, guardian, employer, clergy member or similar. In those situations the general age of consent is not the operative rule.
Marriage is a third, governed by its own statutes that frequently do not match. Seventeen states plus the District of Columbia now prohibit marriage under 18 outright.
Using this information
Treat a state's age of consent as the entry point to its statutory scheme, not as a conclusion. The state guides set out the surrounding rules — close-in-age provisions, penalty tiers, registration consequences and limitations periods — because those are usually what determine an outcome.
If you are dealing with an actual situation rather than researching, speak to an attorney licensed in the relevant state. Statutes are amended, appellate courts reinterpret them, and the facts that matter in a real case are rarely the ones a summary captures.