Orbital period in days to astronomical units
Type a value in d to get it in AU instantly.
0.01957AU
Nothing on our list is smaller: Mercury is 20× further. A year out there lasts about 0.002738 Earth years.
Convert the other way: AU to d
What it means
How long is its year?
Kepler’s law here assumes the Sun’s mass and a circular orbit. Real orbits are ellipses, and the semi-major axis is what goes into the formula.
The math
How to convert d to AU
Kepler’s third law: period in years = (distance in AU)^1.5, and back again distance = period^(2/3). Orbital speed falls as 29.78 ÷ √distance km/s.
Example: 1 d = 0.0195707 AU.
Every unit
Your orbit in every unit
Tables
d to AU conversion table
| d | AU |
|---|---|
| 0.39 d | 0.0104468 AU |
| 0.72 d | 0.0157215 AU |
| 1 d | 0.0195707 AU |
| 1.52 d | 0.0258723 AU |
| 2.8 d | 0.0388787 AU |
| 5.2 d | 0.0587411 AU |
| 9.5 d | 0.0877854 AU |
| 19.2 d | 0.140327 AU |
| 30.1 d | 0.189373 AU |
| 39.5 d | 0.226989 AU |
| 100 d | 0.421638 AU |
AU to d conversion table
| AU | d |
|---|---|
| 0.39 AU | 88.9584 d |
| 0.72 AU | 223.146 d |
| 1 AU | 365.25 d |
| 1.52 AU | 684.472 d |
| 2.8 AU | 1,711.3 d |
| 5.2 AU | 4,331.07 d |
| 9.5 AU | 10,694.9 d |
| 19.2 AU | 30,728.6 d |
| 30.1 AU | 60,317 d |
| 39.5 AU | 90,674.6 d |
| 100 AU | 365,250 d |
Quick answers
Quick answers
- How many AU is 1 d?
- 1 d is 0.0195707 AU.
- How many AU is 10 d?
- 10 d is 0.0908392 AU.
The units
About these units
Orbital period in days (d)
The same period in days, for the fast inner orbits.
Astronomical units (AU)
The Earth–Sun distance, the natural ruler for the solar system.
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