Earth Orbit Semi-Major Axis
| Value | 1.495982612e11 m |
| Status | Conventional / typical value |
| Source | JPL Keplerian elements for the Earth–Moon barycentre, epoch J2000 |
| Categories | Astronomical |
| Planck length | 9.2558576e+45 lP |
| femtometer | 1.4959826e+26 fm |
| picometer | 1.4959826e+23 pm |
| bohr radius | 2.8269974e+21 a0 |
| angstrom | 1.4959826e+21 Å |
| nanometer | 1.4959826e+20 nm |
| micrometer | 1.4959826e+17 μm |
| thou | 5.8896953e+15 thou |
| point | 424,058,060,000,000 pt |
| millimeter | 149,598,260,000,000 mm |
| pica | 35,338,172,000,000 pc |
| centimeter | 14,959,826,000,000 cm |
| inch | 5,889,695,300,000 in |
| decimeter | 1,495,982,600,000 dm |
| hand | 1,472,423,800,000 hh |
| link | 743,648,400,000 li |
| foot | 490,807,940,000 ft |
| US survey foot | 490,806,960,000 ftUS |
| yard | 163,602,650,000 yd |
| meter | 149,598,260,000 m |
| fathom | 81,801,324,000 ftm |
| rod | 29,745,936,000 rd |
| chain | 7,436,484,000 ch |
| cable length | 807,765,990 cb |
| furlong | 743,648,400 fur |
| kilometer | 149,598,260 km |
| mile | 92,956,050 mi |
| nautical mile | 80,776,599 nmi |
| league | 30,985,350 lea |
| megameter | 149,598.26 Mm |
| Earth radius | 23,481.127 REarth |
| light-second | 499.00609 ls |
| lunar distance | 389.17443 LD |
| solar radius | 215.03272 Rsun |
| light-minute | 8.3167681 lmin |
| astronomical unit | 1.0000026 AU |
| light-year | 0.000015812549 ly |
| parsec | 0.0000048481495 pc |
| kiloparsec | 4.8481495e-09 kpc |
| megaparsec | 4.8481495e-12 Mpc |
| gigaparsec | 4.8481495e-15 Gpc |
Learning zone
It is worth stating plainly that the astronomical unit and Earth's mean distance from the Sun are two different things. The au was defined in terms of Earth's orbit historically, but since 2012 it is just a fixed number of metres. Earth's semi-major axis is a measured orbital element that drifts by parts per million as Jupiter, Venus and the rest tug on us, and the value quoted here — 1.000 002 61 au for the Earth–Moon barycentre at J2000 — is a mean over those perturbations, not a permanent property.
"Mean distance" also hides an ambiguity. The semi-major axis is the average of perihelion (147.10 million km) and aphelion (152.10 million km), but the time-averaged distance is slightly larger still, because Earth spends more of the year on the slow outer part of the ellipse.