| astronomical unit | 1 AU | 2 AU | 3 AU | 4 AU | 5 AU | 6 AU | 7 AU | 8 AU | 9 AU | 10 AU | 11 AU | 12 AU | 13 AU | 14 AU | 15 AU | 16 AU | 17 AU | 18 AU | 19 AU | 20 AU | 21 AU | 22 AU | 23 AU | 24 AU | 25 AU | 26 AU | 27 AU | 28 AU | 29 AU | 30 AU | 31 AU | 32 AU | 33 AU | 34 AU | 35 AU | 36 AU | 37 AU | 38 AU | 39 AU | 40 AU | 41 AU | 42 AU | 43 AU | 44 AU | 45 AU | 46 AU | 47 AU | 48 AU | 49 AU | 50 AU | 51 AU | 52 AU | 53 AU | 54 AU | 55 AU | 56 AU | 57 AU | 58 AU | 59 AU | 60 AU | 61 AU | 62 AU | 63 AU | 64 AU | 65 AU | 66 AU | 67 AU | 68 AU | 69 AU | 70 AU | 71 AU | 72 AU | 73 AU | 74 AU | 75 AU | 76 AU | 77 AU | 78 AU | 79 AU | 80 AU | 81 AU | 82 AU | 83 AU | 84 AU | 85 AU | 86 AU | 87 AU | 88 AU | 89 AU | 90 AU | 91 AU | 92 AU | 93 AU | 94 AU | 95 AU | 96 AU | 97 AU | 98 AU | 99 AU | 100 AU |
| earth radius | 23,481.0658766 R⊕ | 46,962.1317533 R⊕ | 70,443.1976299 R⊕ | 93,924.2635065 R⊕ | 117,405.3293831 R⊕ | 140,886.3952598 R⊕ | 164,367.4611364 R⊕ | 187,848.5270130 R⊕ | 211,329.5928897 R⊕ | 234,810.6587663 R⊕ | 258,291.7246429 R⊕ | 281,772.7905195 R⊕ | 305,253.8563962 R⊕ | 328,734.9222728 R⊕ | 352,215.9881494 R⊕ | 375,697.0540261 R⊕ | 399,178.1199027 R⊕ | 422,659.1857793 R⊕ | 446,140.2516559 R⊕ | 469,621.3175326 R⊕ | 493,102.3834092 R⊕ | 516,583.4492858 R⊕ | 540,064.5151625 R⊕ | 563,545.5810391 R⊕ | 587,026.6469157 R⊕ | 610,507.7127923 R⊕ | 633,988.7786690 R⊕ | 657,469.8445456 R⊕ | 680,950.9104222 R⊕ | 704,431.9762989 R⊕ | 727,913.0421755 R⊕ | 751,394.1080521 R⊕ | 774,875.1739287 R⊕ | 798,356.2398054 R⊕ | 821,837.305682 R⊕ | 845,318.3715586 R⊕ | 868,799.4374353 R⊕ | 892,280.5033119 R⊕ | 915,761.5691885 R⊕ | 939,242.6350651 R⊕ | 962,723.7009418 R⊕ | 986,204.7668184 R⊕ | 1,009,685.832695 R⊕ | 1,033,166.8985717 R⊕ | 1,056,647.9644483 R⊕ | 1,080,129.0303249 R⊕ | 1,103,610.0962015 R⊕ | 1,127,091.1620782 R⊕ | 1,150,572.2279548 R⊕ | 1,174,053.2938314 R⊕ | 1,197,534.3597081 R⊕ | 1,221,015.4255847 R⊕ | 1,244,496.4914613 R⊕ | 1,267,977.5573379 R⊕ | 1,291,458.6232146 R⊕ | 1,314,939.6890912 R⊕ | 1,338,420.7549678 R⊕ | 1,361,901.8208445 R⊕ | 1,385,382.8867211 R⊕ | 1,408,863.9525977 R⊕ | 1,432,345.0184743 R⊕ | 1,455,826.084351 R⊕ | 1,479,307.1502276 R⊕ | 1,502,788.2161042 R⊕ | 1,526,269.2819809 R⊕ | 1,549,750.3478575 R⊕ | 1,573,231.4137341 R⊕ | 1,596,712.4796107 R⊕ | 1,620,193.5454874 R⊕ | 1,643,674.611364 R⊕ | 1,667,155.6772406 R⊕ | 1,690,636.7431173 R⊕ | 1,714,117.8089939 R⊕ | 1,737,598.8748705 R⊕ | 1,761,079.9407471 R⊕ | 1,784,561.0066238 R⊕ | 1,808,042.0725004 R⊕ | 1,831,523.138377 R⊕ | 1,855,004.2042536 R⊕ | 1,878,485.2701303 R⊕ | 1,901,966.3360069 R⊕ | 1,925,447.4018835 R⊕ | 1,948,928.4677602 R⊕ | 1,972,409.5336368 R⊕ | 1,995,890.5995134 R⊕ | 2,019,371.66539 R⊕ | 2,042,852.7312667 R⊕ | 2,066,333.7971433 R⊕ | 2,089,814.8630199 R⊕ | 2,113,295.9288966 R⊕ | 2,136,776.9947732 R⊕ | 2,160,258.0606498 R⊕ | 2,183,739.1265264 R⊕ | 2,207,220.1924031 R⊕ | 2,230,701.2582797 R⊕ | 2,254,182.3241563 R⊕ | 2,277,663.390033 R⊕ | 2,301,144.4559096 R⊕ | 2,324,625.5217862 R⊕ | 2,348,106.5876628 R⊕ |
The astronomical unit (symbol: au or ua) is a unit of length, roughly the distance from Earth to the Sun. However, that distance varies as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once a year. Originally conceived as the average of Earth's aphelion and perihelion, it is now defined as exactly 149 597 870 700 metres (about 150 million kilometres, or 93 million miles). The astronomical unit is used primarily as a convenient yardstick for measuring distances within the Solar System or around other stars. However, it is also a fundamental component in the definition of another unit of astronomical length, the parsec.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| astronomical unit | AU | ≡ 149 597 870 700 m ≈ Distance from Earth to Sun | ≡ 149 597 870 700 m | Science - Astronomy (Length) |
| astronomical units | earth radius | astronomical units | earth radius |
|---|---|---|---|
| 1 | ≈ 23481.065876628 | 4 | ≈ 93924.263506514 |
| 1.5 | ≈ 35221.598814943 | 4.5 | ≈ 105664.79644483 |
| 2 | ≈ 46962.131753257 | 5 | ≈ 117405.32938314 |
| 2.5 | ≈ 58702.664691571 | 5.5 | ≈ 129145.86232146 |
| 3 | ≈ 70443.197629885 | 6 | ≈ 140886.39525977 |
Earth radius is the distance from Earth's center to its surface, about 6,371 km (3,959 mi). This length is also used as a unit of distance, especially in astronomy and geology, where it is usually denoted by R⊕.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| earth radius | R⊕ | ≈ 6,371 km | ≈ 6,371 km | Science - Astronomy (Length) |
| earth radius | astronomical units | earth radius | astronomical units |
|---|---|---|---|
| 1 | ≈ 4.2587504555972E-5 | 4 | ≈ 0.00017035001822389 |
| 1.5 | ≈ 6.3881256833958E-5 | 4.5 | ≈ 0.00019164377050188 |
| 2 | ≈ 8.5175009111945E-5 | 5 | ≈ 0.00021293752277986 |
| 2.5 | ≈ 0.00010646876138993 | 5.5 | ≈ 0.00023423127505785 |
| 3 | ≈ 0.00012776251366792 | 6 | ≈ 0.00025552502733583 |
| astronomical units | earth radius |
|---|---|
| 1 | ≈ 23,481.0658766 |
| 4.2587504555972 × 10-5 | ≈ 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |