How long does it take for the Earth to circle the sun?

It's known as a year.

A year is the name given to Earth's orbital period around the Sun; there are a few slightly different definitions of what a year is, though.

The majority of years are 365 days long, with every fourth year being a leap year, which is 366 days long. Centuries are only leap years if the year is divisible by 400. For example, the year 2000 was a leap year, but the year 1900 was not. The Gregorian average year, or calendar year, is 365.2425 days long.

The Julian year is used in astronomical computations and has a length of precisely 365.25 days.

The time between two consecutive Vernal Equinoxes is known as the tropical year, and it has a length of 356.24219 days. Because of the equinox precession, the tropical year is marginally shorter than other definitions of years.

The anomalistic year is defined as the period of time between two successive perihelions and has a length of 365.259636 days. The anomalistic year is slightly longer than other year definitions because of the precession of perihelion, and it actually varies by a few days due to perturbations in Earth's orbits caused by the gravitational pull of other planets.

The sidereal year, which lasts for 365.256363 days, is the amount of time it takes for the Earth to complete one orbit around a fixed star.

It takes approximately 365.25 days for the Earth to complete one orbit around the Sun.