How long is Earth's orbit?

Earth takes 365.3 days to go once round the Sun. It is travelling at 29.84 km/s at the moment — a speed that changes through the orbit, fastest at perihelion and slowest at aphelion.

What shape is Earth's orbit?

An ellipse with the Sun at one focus, not at the centre. Its eccentricity is 0.0167, derived here from the perihelion and aphelion distances rather than quoted: 0.983 AU at closest and 1.017 AU at furthest, a difference of 4,996,217 km.

Where is Earth in its orbit now?

0.999 AU from the Sun — 0.149 billion km — which is 46% of the way from its closest point to its furthest. It next reaches perihelion on 3 January 2027.

Earth

Earth's orbit

Once round the Sun every 365.3 days, on an ellipse drawn here from the ephemeris rather than from a formula.

Looking down on the plane of the ecliptic, traced from the ephemeris over one full orbit of 365 days. Mars’s orbit is the faint one, for scale. The Sun sits off the centre of the ellipse — that offset is the eccentricity, and it is why the two distances differ.

Orbital period: 365.3; days for one lap
Eccentricity: 0.0167; 0 would be a circle
Semi-major axis: 1.000; AU · the orbit's average radius
Speed now: 29.84; km/s, from the ephemeris

What is worth knowing about it

Earth is closest to the Sun in early January and furthest in early July — the opposite of what most northern-hemisphere readers expect. Seasons come from axial tilt, not from this three per cent swing in distance.

The shape of it

Earth does not travel a circle. It comes as close as 0.983 AU (0.147 billion km) and goes as far as 1.017 AU (0.152 billion km) — aphelion is 1.03 times further out than perihelion, a swing of 4,996,217 km. At 0.0167 its orbit is very nearly a circle — draw it to scale and the difference from one would be thinner than the line.

Because the Sun sits at a focus rather than the centre, Earth does not move at a constant speed either. It runs fastest when it is closest and slowest when it is furthest, sweeping equal areas in equal times — which is Kepler's second law, and is visible in the diagram above as the uneven spacing of a constant time step.

Where it is now

Today Earth is 0.999 AU from the Sun, 46% of the way from perihelion to aphelion, travelling at 29.84 km/s. It reaches perihelion on 3 January 2027 at 0.983 AU.

Common questions

How long is Earth's orbit?: Earth takes 365.3 days to go once round the Sun. It is travelling at 29.84 km/s at the moment — a speed that changes through the orbit, fastest at perihelion and slowest at aphelion.
What shape is Earth's orbit?: An ellipse with the Sun at one focus, not at the centre. Its eccentricity is 0.0167, derived here from the perihelion and aphelion distances rather than quoted: 0.983 AU at closest and 1.017 AU at furthest, a difference of 4,996,217 km.
Where is Earth in its orbit now?: 0.999 AU from the Sun — 0.149 billion km — which is 46% of the way from its closest point to its furthest. It next reaches perihelion on 3 January 2027.

Positions from VSOP87 via Astronomy Engine, accurate to within one arcminute. The orbit above is traced by sampling a full period rather than drawn from elements, so the tilt and the off-centre Sun are the real ones. See Earth’s distance from the Sun, Earth right now, or watch the whole system move in the live simulation.