light-year | 1 ly | 2 ly | 3 ly | 4 ly | 5 ly | 6 ly | 7 ly | 8 ly | 9 ly | 10 ly | 11 ly | 12 ly | 13 ly | 14 ly | 15 ly | 16 ly | 17 ly | 18 ly | 19 ly | 20 ly | 21 ly | 22 ly | 23 ly | 24 ly | 25 ly | 26 ly | 27 ly | 28 ly | 29 ly | 30 ly | 31 ly | 32 ly | 33 ly | 34 ly | 35 ly | 36 ly | 37 ly | 38 ly | 39 ly | 40 ly | 41 ly | 42 ly | 43 ly | 44 ly | 45 ly | 46 ly | 47 ly | 48 ly | 49 ly | 50 ly | 51 ly | 52 ly | 53 ly | 54 ly | 55 ly | 56 ly | 57 ly | 58 ly | 59 ly | 60 ly | 61 ly | 62 ly | 63 ly | 64 ly | 65 ly | 66 ly | 67 ly | 68 ly | 69 ly | 70 ly | 71 ly | 72 ly | 73 ly | 74 ly | 75 ly | 76 ly | 77 ly | 78 ly | 79 ly | 80 ly | 81 ly | 82 ly | 83 ly | 84 ly | 85 ly | 86 ly | 87 ly | 88 ly | 89 ly | 90 ly | 91 ly | 92 ly | 93 ly | 94 ly | 95 ly | 96 ly | 97 ly | 98 ly | 99 ly | 100 ly |
foot, metric | 2.9916817627839 × 1016 mf | 5.9833635255679 × 1016 mf | 8.9750452883518 × 1016 mf | 1.1966727051136 × 1017 mf | 1.495840881392 × 1017 mf | 1.7950090576704 × 1017 mf | 2.0941772339488 × 1017 mf | 2.3933454102271 × 1017 mf | 2.6925135865055 × 1017 mf | 2.9916817627839 × 1017 mf | 3.2908499390623 × 1017 mf | 3.5900181153407 × 1017 mf | 3.8891862916191 × 1017 mf | 4.1883544678975 × 1017 mf | 4.4875226441759 × 1017 mf | 4.7866908204543 × 1017 mf | 5.0858589967327 × 1017 mf | 5.3850271730111 × 1017 mf | 5.6841953492895 × 1017 mf | 5.9833635255679 × 1017 mf | 6.2825317018463 × 1017 mf | 6.5816998781247 × 1017 mf | 6.8808680544031 × 1017 mf | 7.1800362306814 × 1017 mf | 7.4792044069598 × 1017 mf | 7.7783725832382 × 1017 mf | 8.0775407595166 × 1017 mf | 8.376708935795 × 1017 mf | 8.6758771120734 × 1017 mf | 8.9750452883518 × 1017 mf | 9.2742134646302 × 1017 mf | 9.5733816409086 × 1017 mf | 9.872549817187 × 1017 mf | 1.0171717993465 × 1018 mf | 1.0470886169744 × 1018 mf | 1.0770054346022 × 1018 mf | 1.1069222522301 × 1018 mf | 1.1368390698579 × 1018 mf | 1.1667558874857 × 1018 mf | 1.1966727051136 × 1018 mf | 1.2265895227414 × 1018 mf | 1.2565063403693 × 1018 mf | 1.2864231579971 × 1018 mf | 1.3163399756249 × 1018 mf | 1.3462567932528 × 1018 mf | 1.3761736108806 × 1018 mf | 1.4060904285085 × 1018 mf | 1.4360072461363 × 1018 mf | 1.4659240637641 × 1018 mf | 1.495840881392 × 1018 mf | 1.5257576990198 × 1018 mf | 1.5556745166476 × 1018 mf | 1.5855913342755 × 1018 mf | 1.6155081519033 × 1018 mf | 1.6454249695312 × 1018 mf | 1.675341787159 × 1018 mf | 1.7052586047868 × 1018 mf | 1.7351754224147 × 1018 mf | 1.7650922400425 × 1018 mf | 1.7950090576704 × 1018 mf | 1.8249258752982 × 1018 mf | 1.854842692926 × 1018 mf | 1.8847595105539 × 1018 mf | 1.9146763281817 × 1018 mf | 1.9445931458096 × 1018 mf | 1.9745099634374 × 1018 mf | 2.0044267810652 × 1018 mf | 2.0343435986931 × 1018 mf | 2.0642604163209 × 1018 mf | 2.0941772339488 × 1018 mf | 2.1240940515766 × 1018 mf | 2.1540108692044 × 1018 mf | 2.1839276868323 × 1018 mf | 2.2138445044601 × 1018 mf | 2.243761322088 × 1018 mf | 2.2736781397158 × 1018 mf | 2.3035949573436 × 1018 mf | 2.3335117749715 × 1018 mf | 2.3634285925993 × 1018 mf | 2.3933454102271 × 1018 mf | 2.423262227855 × 1018 mf | 2.4531790454828 × 1018 mf | 2.4830958631107 × 1018 mf | 2.5130126807385 × 1018 mf | 2.5429294983663 × 1018 mf | 2.5728463159942 × 1018 mf | 2.602763133622 × 1018 mf | 2.6326799512499 × 1018 mf | 2.6625967688777 × 1018 mf | 2.6925135865055 × 1018 mf | 2.7224304041334 × 1018 mf | 2.7523472217612 × 1018 mf | 2.7822640393891 × 1018 mf | 2.8121808570169 × 1018 mf | 2.8420976746447 × 1018 mf | 2.8720144922726 × 1018 mf | 2.9019313099004 × 1018 mf | 2.9318481275283 × 1018 mf | 2.9617649451561 × 1018 mf | 2.9916817627839 × 1018 mf |
The light-year is a unit of length used to express astronomical distances. It is about 9.5 quadrillion metres or 5.9 trillion miles. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Because it includes the word "year", the term light-year is sometimes misinterpreted as a unit of time.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
light-year | ly | ≡ Distance light travels in vacuum in 365.25 days | = 9.4607304725808×1015 m | Science - Astronomy (Length) |
light-years | feet, metric | light-years | feet, metric |
---|---|---|---|
1 | ≈ 2.9916817627839E+16 | 4 | ≈ 1.1966727051136E+17 |
1.5 | ≈ 4.4875226441759E+16 | 4.5 | ≈ 1.3462567932528E+17 |
2 | ≈ 5.9833635255679E+16 | 5 | ≈ 1.495840881392E+17 |
2.5 | ≈ 7.4792044069598E+16 | 5.5 | ≈ 1.6454249695312E+17 |
3 | ≈ 8.9750452883518E+16 | 6 | ≈ 1.7950090576704E+17 |
A metric foot is a nickname for a preferred number length of 3 basic modules (3 M), or 30 centimetres (11.811 in). The 30 cm metric ruler was a similar length to the traditional imperial one-foot ruler. A metric foot is 4.8 millimetres (0.189 in) shorter than an imperial foot.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
foot, metric | mf | ≡ √ 1⁄10 m | ≈ 0.31622776602 m | Metric system Non-SI |
feet, metric | light-years | feet, metric | light-years |
---|---|---|---|
1 | ≈ 3.342601517447E-17 | 4 | ≈ 1.3370406069788E-16 |
1.5 | ≈ 5.0139022761704E-17 | 4.5 | ≈ 1.5041706828511E-16 |
2 | ≈ 6.6852030348939E-17 | 5 | ≈ 1.6713007587235E-16 |
2.5 | ≈ 8.3565037936174E-17 | 5.5 | ≈ 1.8384308345958E-16 |
3 | ≈ 1.0027804552341E-16 | 6 | ≈ 2.0055609104682E-16 |
light-years | feet, metric |
---|---|
1 | ≈ 2.9916817627839 × 1016 |
3.342601517447 × 10-17 | ≈ 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 …) |