| 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 " |
| degree | 0.0002778 ° | 0.0005556 ° | 0.0008333 ° | 0.0011111 ° | 0.0013889 ° | 0.0016667 ° | 0.0019444 ° | 0.0022222 ° | 0.0025 ° | 0.0027778 ° | 0.0030556 ° | 0.0033333 ° | 0.0036111 ° | 0.0038889 ° | 0.0041667 ° | 0.0044444 ° | 0.0047222 ° | 0.005 ° | 0.0052778 ° | 0.0055556 ° | 0.0058333 ° | 0.0061111 ° | 0.0063889 ° | 0.0066667 ° | 0.0069444 ° | 0.0072222 ° | 0.0075 ° | 0.0077778 ° | 0.0080556 ° | 0.0083333 ° | 0.0086111 ° | 0.0088889 ° | 0.0091667 ° | 0.0094444 ° | 0.0097222 ° | 0.01 ° | 0.0102778 ° | 0.0105556 ° | 0.0108333 ° | 0.0111111 ° | 0.0113889 ° | 0.0116667 ° | 0.0119444 ° | 0.0122222 ° | 0.0125 ° | 0.0127778 ° | 0.0130556 ° | 0.0133333 ° | 0.0136111 ° | 0.0138889 ° | 0.0141667 ° | 0.0144444 ° | 0.0147222 ° | 0.015 ° | 0.0152778 ° | 0.0155556 ° | 0.0158333 ° | 0.0161111 ° | 0.0163889 ° | 0.0166667 ° | 0.0169444 ° | 0.0172222 ° | 0.0175 ° | 0.0177778 ° | 0.0180556 ° | 0.0183333 ° | 0.0186111 ° | 0.0188889 ° | 0.0191667 ° | 0.0194444 ° | 0.0197222 ° | 0.02 ° | 0.0202778 ° | 0.0205556 ° | 0.0208333 ° | 0.0211111 ° | 0.0213889 ° | 0.0216667 ° | 0.0219444 ° | 0.0222222 ° | 0.0225 ° | 0.0227778 ° | 0.0230556 ° | 0.0233333 ° | 0.0236111 ° | 0.0238889 ° | 0.0241667 ° | 0.0244444 ° | 0.0247222 ° | 0.025 ° | 0.0252778 ° | 0.0255556 ° | 0.0258333 ° | 0.0261111 ° | 0.0263889 ° | 0.0266667 ° | 0.0269444 ° | 0.0272222 ° | 0.0275 ° | 0.0277778 ° |
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 | degrees | arcseconds | degrees |
|---|---|---|---|
| 1 | ≈ 0.00027777777777778 | 6 | ≈ 0.0016666666666667 |
| 2 | ≈ 0.00055555555555556 | 7 | ≈ 0.0019444444444444 |
| 3 | ≈ 0.00083333333333333 | 8 | ≈ 0.0022222222222222 |
| 4 | ≈ 0.0011111111111111 | 9 | ≈ 0.0025 |
| 5 | ≈ 0.0013888888888889 | 10 | ≈ 0.0027777777777778 |
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane angle, defined so that a full rotation is 360 degrees.
It is not an SI unit, as the SI unit of angular measure is the radian, but it is mentioned in the SI brochure as an accepted unit.Because a full rotation equals 2π radians, one degree is equivalent to π/180 radians.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| degree | ° | ≡ 1⁄360 of a revolution ≡ π⁄180 rad | ≈ 17.453293×10−3 rad | Metric system SI |
| degrees | arcseconds | degrees | arcseconds |
|---|---|---|---|
| 1 | ≈ 3600 | 6 | ≈ 21600 |
| 2 | ≈ 7200 | 7 | ≈ 25200 |
| 3 | ≈ 10800 | 8 | ≈ 28800 |
| 4 | ≈ 14400 | 9 | ≈ 32400 |
| 5 | ≈ 18000 | 10 | ≈ 36000 |
| arcseconds | degrees |
|---|---|
| 1 | ≈ 0.0002778 |
| 3 600 | ≈ 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 …) |