By Alexander Merz · Published on · Details checked on 25 October 2026
Short answer: Exactly 365 days, 5 hours, 48 minutes and 45 seconds (tropical year). Because of the remaining almost 6 hours, there is a leap day on 29 February every four years.
More in the overview: The Solar System.
A year is not a round number
The Earth circles the Sun on an orbit 940 million kilometres long at an average of 107,000 km/h (29.8 km per second!). The fact that this does not come out at a neat 365 days forces us into calendar acrobatics: the Julian calendar introduced the leap day, the Gregorian calendar refined the rule (century years are leap years only every 400 years) – otherwise the calendar would drift by almost 8 days against the seasons every millennium.
An ellipse and a common myth
The Earth’s orbit is slightly elliptical: in early January we are closest to the Sun (perihelion, 147.1 million km), in early July farthest away (aphelion, 152.1 million km). So in the northern winter we are closest to the Sun! The seasons are not caused by the distance but by the tilt of the Earth’s axis of 23.4 degrees – all the dates are in our article on the astronomical seasons.
Sidereal or tropical?
Astronomers distinguish two years: the sidereal year (365d 6h 9min) is one full lap relative to the fixed stars. The tropical year (365d 5h 49min) runs from the start of spring to the start of spring – because of the precession of the Earth’s axis it is about 20 minutes shorter and is the measure of our calendar.
Frequently asked questions
How fast does the Earth travel around the Sun?
At an average of 29.8 km/s – around 107,000 km/h. In the time it takes to read this sentence: more than 100 kilometres.
Why are there leap years?
The year lasts ~365.24 days. The leap day every 4 years (with the 100/400-year exception) keeps the calendar in step with the seasons.
Is the Earth closer to the Sun in summer?
Not in the northern hemisphere – in early July it is farthest from the Sun. The seasons are made by the axial tilt, not the distance.
How long is the Earth’s orbit?
Around 940 million kilometres per orbit.