Second of Arc to Degree Conversion Chart
| Second of arc (arcsec) | Degree (deg) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 1.08 arcsec | 0.0003 deg | One Arcsecond Astronomical Stellar Parallax Baseline | 1.08 × 0.000278 = 0.0003 deg |
| 3.6 arcsec | 0.001 deg | High-Resolution Orbital Space Telescope Pointing Stability | 3.6 × 0.000278 = 0.001 deg |
| 18 arcsec | 0.005 deg | Eighteen Arcseconds Atmospheric Optical Seeing Limit | 18 × 0.000278 = 0.005 deg |
| 36 arcsec | 0.01 deg | Jupiter Maximum Apparent Disc Diameter Viewed from Earth | 36 × 0.000278 = 0.01 deg |
| 180 arcsec | 0.05 deg | One-Twentieth of a Degree Geodetic Polygon Misclosure | 180 × 0.000278 = 0.05 deg |
| 360 arcsec | 0.1 deg | One-Tenth Degree Astronomical Calibration Grid Sector | 360 × 0.000278 = 0.1 deg |
| 900 arcsec | 0.25 deg | Quarter Degree Marine Radar High-Precision Sector Span | 900 × 0.000278 = 0.25 deg |
| 1800 arcsec | 0.5 deg | Lunar Angular Diameter Approximate Midpoint in Arcseconds | 1800 × 0.000278 = 0.5 deg |
| 3600 arcsec | 1 deg | Exact International Definition of 3,600 Arcseconds in Degree | 3600 × 0.000278 = 1 deg |
| 7200 arcsec | 2 deg | Two Degrees Geodetic Triangulation Baseline in Arcseconds | 7200 × 0.000278 = 2 deg |
| 18000 arcsec | 5 deg | Five Degrees Wide-Field Astrophotography Lens Coverage | 18000 × 0.000278 = 5 deg |
| 36000 arcsec | 10 deg | Ten Degrees Visual Constellation Quadrant in Arcseconds | 36000 × 0.000278 = 10 deg |
| 54000 arcsec | 15 deg | One Hour Earth Rotation Angle Expressed in Arcseconds | 54000 × 0.000278 = 15 deg |
| 108000 arcsec | 30 deg | Thirty Degrees Zodiac Astronomical House Angular Breadth | 108000 × 0.000278 = 30 deg |
| 324000 arcsec | 90 deg | Ninety Degrees Right Angle Perpendicular in Arcseconds | 324000 × 0.000278 = 90 deg |
Second of arc to Degree Formula & Unit Definitions
The conversion from seconds of arc to degrees is governed by the exact rational factor of 1/3,600 (1 arcsec = 1/3,600° ≈ 0.000277778°). To convert arcseconds to degrees, divide the arcsecond value by 3,600 (or multiply by ~0.000278). Conversely, to convert degrees into arcseconds, multiply degrees by 3,600.
Quick Estimation: Divide the arcsecond value by 36, then shift the decimal point two places to the left (divide by 3,600). For example: 3,600 arcsec / 3,600 = 1°; 1,800 arcsec / 3,600 = 0.5°; 900 arcsec / 3,600 = 0.25°; 36,000 arcsec / 3,600 = 10°.
Second of Arc (arcsec / ″)
Fine Sexagesimal Division (1/3,600°)- Creator & Origin: Ptolemy's Hellenistic astronomy and Bessel's 19th-century stellar parallax measurements.
- Standard Definition: Defined as exactly 1/3,600 of an angular degree (1 arcsec ≈ 0.000277778°).
- Everyday Focus: Space telescope pointing, semiconductor lithography, atmospheric seeing, and stellar drift.
Degree Angle (°)
Sexagesimal Base Unit- Creator & Origin: Babylonian astronomers tracking 360-day calendar paths across the celestial sphere.
- Standard Definition: Defined as exactly 1/360 of a circle (90° = 1 right angle).
- Everyday Focus: GPS coordinates (decimal degrees), flight navigation, CAD drawings, and robotics.
Frequently Asked Questions
Q.How many degrees are in one second of arc?
One second of arc equals exactly 1/3,600 of a degree (approximately 0.000277778°).
Q.What is the reverse conversion from degrees to arcseconds?
To convert back, use the Degree to Second of Arc Converter where 1° equals 3,600 arcsec.
Q.How many degrees is 1,800 arcseconds?
1,800 arcseconds equals exactly 0.5 degrees (30 arcminutes).
Q.How many degrees is 3,600 arcseconds?
3,600 arcseconds equals exactly 1 degree.
Q.How do you convert arcseconds to degrees?
Divide the number of arcseconds by 3,600 (e.g. 7,200 arcsec / 3,600 = 2°).