| arcsecond | 1 " | 2 " | 3 " | 4 " | 5 " | 6 " | 7 " | 8 " | 9 " | 10 " | 11 " | 12 " | 13 " | 14 " | 15 " | 16 " | 17 " | 18 " | 19 " | 20 " | 21 " | 22 " | 23 " | 24 " | 25 " | 26 " | 27 " | 28 " | 29 " | 30 " | 31 " | 32 " | 33 " | 34 " | 35 " | 36 " | 37 " | 38 " | 39 " | 40 " | 41 " | 42 " | 43 " | 44 " | 45 " | 46 " | 47 " | 48 " | 49 " | 50 " | 51 " | 52 " | 53 " | 54 " | 55 " | 56 " | 57 " | 58 " | 59 " | 60 " | 61 " | 62 " | 63 " | 64 " | 65 " | 66 " | 67 " | 68 " | 69 " | 70 " | 71 " | 72 " | 73 " | 74 " | 75 " | 76 " | 77 " | 78 " | 79 " | 80 " | 81 " | 82 " | 83 " | 84 " | 85 " | 86 " | 87 " | 88 " | 89 " | 90 " | 91 " | 92 " | 93 " | 94 " | 95 " | 96 " | 97 " | 98 " | 99 " | 100 " |
| radian | 4.8481367283951 × 10-6 rad | 9.6962734567901 × 10-6 rad | 1.4544410185185 × 10-5 rad | 1.939254691358 × 10-5 rad | 2.4240683641975 × 10-5 rad | 2.908882037037 × 10-5 rad | 3.3936957098765 × 10-5 rad | 3.878509382716 × 10-5 rad | 4.3633230555556 × 10-5 rad | 4.8481367283951 × 10-5 rad | 5.3329504012346 × 10-5 rad | 5.8177640740741 × 10-5 rad | 6.3025777469136 × 10-5 rad | 6.7873914197531 × 10-5 rad | 7.2722050925926 × 10-5 rad | 7.7570187654321 × 10-5 rad | 8.2418324382716 × 10-5 rad | 8.7266461111111 × 10-5 rad | 9.2114597839506 × 10-5 rad | 9.6962734567901 × 10-5 rad | 0.0001018 rad | 0.0001067 rad | 0.0001115 rad | 0.0001164 rad | 0.0001212 rad | 0.0001261 rad | 0.0001309 rad | 0.0001357 rad | 0.0001406 rad | 0.0001454 rad | 0.0001503 rad | 0.0001551 rad | 0.0001600 rad | 0.0001648 rad | 0.0001697 rad | 0.0001745 rad | 0.0001794 rad | 0.0001842 rad | 0.0001891 rad | 0.0001939 rad | 0.0001988 rad | 0.0002036 rad | 0.0002085 rad | 0.0002133 rad | 0.0002182 rad | 0.0002230 rad | 0.0002279 rad | 0.0002327 rad | 0.0002376 rad | 0.0002424 rad | 0.0002473 rad | 0.0002521 rad | 0.0002570 rad | 0.0002618 rad | 0.0002666 rad | 0.0002715 rad | 0.0002763 rad | 0.0002812 rad | 0.0002860 rad | 0.0002909 rad | 0.0002957 rad | 0.0003006 rad | 0.0003054 rad | 0.0003103 rad | 0.0003151 rad | 0.0003200 rad | 0.0003248 rad | 0.0003297 rad | 0.0003345 rad | 0.0003394 rad | 0.0003442 rad | 0.0003491 rad | 0.0003539 rad | 0.0003588 rad | 0.0003636 rad | 0.0003685 rad | 0.0003733 rad | 0.0003782 rad | 0.0003830 rad | 0.0003879 rad | 0.0003927 rad | 0.0003975 rad | 0.0004024 rad | 0.0004072 rad | 0.0004121 rad | 0.0004169 rad | 0.0004218 rad | 0.0004266 rad | 0.0004315 rad | 0.0004363 rad | 0.0004412 rad | 0.0004460 rad | 0.0004509 rad | 0.0004557 rad | 0.0004606 rad | 0.0004654 rad | 0.0004703 rad | 0.0004751 rad | 0.0004800 rad | 0.0004848 rad |
A second of arc, arcsecond (arcsec), arc second, or second arc is a unit of angular measurement equal to 1/3600 of one degree.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| arcsecond | " | ≡ 1°⁄3600 | ≈ 4.848137×10−6 rad | Metric system SI |
| arcseconds | radians | arcseconds | radians |
|---|---|---|---|
| 1 | ≈ 4.8481367283951E-6 | 6 | ≈ 2.908882037037E-5 |
| 2 | ≈ 9.6962734567901E-6 | 7 | ≈ 3.3936957098765E-5 |
| 3 | ≈ 1.4544410185185E-5 | 8 | ≈ 3.878509382716E-5 |
| 4 | ≈ 1.939254691358E-5 | 9 | ≈ 4.3633230555556E-5 |
| 5 | ≈ 2.4240683641975E-5 | 10 | ≈ 4.8481367283951E-5 |
The radian is the standard unit of angular measure, used in many areas of mathematics. The length of an arc of a unit circle is numerically equal to the measurement in radians of the angle that it subtends; one radian is just under 57.3 degrees.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| radian | rad | The angle subtended at the center of a circle by an arc whose length is equal to the circle's radius. One full revolution encompasses 2π radians. | = 1 rad | Metric system SI |
| radians | arcseconds | radians | arcseconds |
|---|---|---|---|
| 1 | ≈ 206264.80976559 | 6 | ≈ 1237588.8585936 |
| 2 | ≈ 412529.61953119 | 7 | ≈ 1443853.6683592 |
| 3 | ≈ 618794.42929678 | 8 | ≈ 1650118.4781248 |
| 4 | ≈ 825059.23906238 | 9 | ≈ 1856383.2878904 |
| 5 | ≈ 1031324.048828 | 10 | ≈ 2062648.0976559 |
| arcseconds | radians |
|---|---|
| 1 | ≈ 4.8481367283951 × 10-6 |
| 206,264.8097656 | ≈ 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 …) |