How far is Mercury from the Sun?

Today, 10 October 2026, Mercury is 66,383,730 km from the Sun — 0.066 billion kilometres, or 0.444 astronomical units. That figure changes constantly: the orbit is an ellipse, so Mercury is closer at one end than the other.

What is Mercury's average distance from the Sun?

0.387 AU — 0.058 billion km. This is the semi-major axis, which is the number most references quote as "the" distance. It is an average, and Mercury is actually at it only twice per orbit.

What are Mercury's closest and furthest distances?

Closest (perihelion) 0.308 AU or 0.046 billion km, next on 10 November 2026. Furthest (aphelion) 0.467 AU or 0.070 billion km, next on 24 December 2026. The difference between them is 23,815,897 km.

How long does sunlight take to reach Mercury?

3.7 minutes at today's distance. Light from the Sun reaches Earth in about 8 minutes 20 seconds, so sunlight arrives at Mercury roughly 0.4 times later than it reaches us.

Mercury

Mercury's distance from the Sun

Not the average everyone quotes — the figure for today, and the two extremes it swings between.

Right now

0.066 billion km

66,383,730 km · 0.444 AU · sunlight takes 3.7 minutes to get there

Computed 10 October 2026 and rebuilt through the day.

Closest to the Sun: 0.308 AU; 0.046 bn km · 10 November 2026
Furthest from the Sun: 0.467 AU; 0.070 bn km · 24 December 2026
Average: 0.387 AU; the figure most tables give
Orbital speed: 41.32 km/s; right now, from the ephemeris

Why there is no single answer

Mercury’s orbit is an ellipse with the Sun at one focus rather than at the centre, so the distance changes continuously. Over one orbit it swings by 23,815,897 km — aphelion is 1.52 times further out than perihelion. At 0.206 this is one of the most elliptical orbits of any major body — far enough from a circle to see it in a drawing without being told.

That is why the number in an encyclopedia and the number here differ. Theirs is the semi-major axis, an average over the whole orbit; this one is where Mercury is today. Both are correct, and they answer different questions.

Looking down on the plane of the ecliptic, traced from the ephemeris over one full orbit of 88 days. Earth’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.

Where it is heading

Mercury reaches perihelion — its closest approach to the Sun — on 10 November 2026, in 1 months, at 0.308 AU. It is currently 86% of the way from perihelion to aphelion, moving at 41.32 km/s.

Distance from Earth is a different question again, and a more variable one: today it is 1.039 AU, and it changes as both planets move. Mercury right now carries that figure.

Common questions

How far is Mercury from the Sun?: Today, 10 October 2026, Mercury is 66,383,730 km from the Sun — 0.066 billion kilometres, or 0.444 astronomical units. That figure changes constantly: the orbit is an ellipse, so Mercury is closer at one end than the other.
What is Mercury's average distance from the Sun?: 0.387 AU — 0.058 billion km. This is the semi-major axis, which is the number most references quote as "the" distance. It is an average, and Mercury is actually at it only twice per orbit.
What are Mercury's closest and furthest distances?: Closest (perihelion) 0.308 AU or 0.046 billion km, next on 10 November 2026. Furthest (aphelion) 0.467 AU or 0.070 billion km, next on 24 December 2026. The difference between them is 23,815,897 km.
How long does sunlight take to reach Mercury?: 3.7 minutes at today's distance. Light from the Sun reaches Earth in about 8 minutes 20 seconds, so sunlight arrives at Mercury roughly 0.4 times later than it reaches us.

Positions from VSOP87 via Astronomy Engine, accurate to within one arcminute. Perihelion and aphelion are found by search rather than taken from a table, which is why the dates are exact and why the extremes differ slightly from one orbit to the next — the other planets pull on this one. See Mercury’s orbit, Mercury right now, or watch it move in the live simulation.