Degree to Second of Arc Conversion Chart
| Degree (deg) | Second of arc (arcsec) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 0.0003 deg | 1.08 arcsec | One Arcsecond Astronomical Stellar Parallax Baseline | 0.0003 × 3600 = 1.08 arcsec |
| 0.001 deg | 3.6 arcsec | High-Resolution Orbital Space Telescope Pointing Stability | 0.001 × 3600 = 3.6 arcsec |
| 0.005 deg | 18 arcsec | Eighteen Arcseconds Atmospheric Optical Seeing Limit | 0.005 × 3600 = 18 arcsec |
| 0.01 deg | 36 arcsec | Jupiter Maximum Apparent Disc Diameter Viewed from Earth | 0.01 × 3600 = 36 arcsec |
| 0.05 deg | 180 arcsec | One-Twentieth of a Degree Geodetic Polygon Misclosure | 0.05 × 3600 = 180 arcsec |
| 0.1 deg | 360 arcsec | One-Tenth Degree Astronomical Calibration Grid Sector | 0.1 × 3600 = 360 arcsec |
| 0.25 deg | 900 arcsec | Quarter Degree Marine Radar High-Precision Sector Span | 0.25 × 3600 = 900 arcsec |
| 0.5 deg | 1800 arcsec | Lunar Angular Diameter Approximate Midpoint in Arcseconds | 0.5 × 3600 = 1800 arcsec |
| 1 deg | 3600 arcsec | Exact International Definition of 3,600 Arcseconds in Degree | 1 × 3600 = 3600 arcsec |
| 2 deg | 7200 arcsec | Two Degrees Geodetic Triangulation Baseline in Arcseconds | 2 × 3600 = 7200 arcsec |
| 5 deg | 18000 arcsec | Five Degrees Wide-Field Astrophotography Lens Coverage | 5 × 3600 = 18000 arcsec |
| 10 deg | 36000 arcsec | Ten Degrees Visual Constellation Quadrant in Arcseconds | 10 × 3600 = 36000 arcsec |
| 15 deg | 54000 arcsec | One Hour Earth Rotation Angle Expressed in Arcseconds | 15 × 3600 = 54000 arcsec |
| 30 deg | 108000 arcsec | Thirty Degrees Zodiac Astronomical House Angular Breadth | 30 × 3600 = 108000 arcsec |
| 90 deg | 324000 arcsec | Ninety Degrees Right Angle Perpendicular in Arcseconds | 90 × 3600 = 324000 arcsec |
Degree to Second of arc Formula & Unit Definitions
The conversion from degrees to seconds of arc is governed by the exact integer factor of 3,600 (1° = 3,600 arcsec). To convert degrees into seconds of arc, multiply the degree value by 3,600 (or multiply by 60 twice). Conversely, to convert seconds of arc back into degrees, divide the arcsecond value by 3,600 (or multiply by ~0.000277778).
Quick Estimation: Multiply degrees by 36, then append two zeros (multiply by 3,600). For example: 0.5° × 3,600 = 1,800 arcsec (half-degree); 1° × 3,600 = 3,600 arcsec; 10° × 3,600 = 36,000 arcsec.
Degree Angle (°)
Sexagesimal Circle Division- Creator & Origin: Babylonian sexagesimal astronomy dividing the yearly solar path into 360 degrees.
- Standard Definition: Defined as exactly 1/360 of a complete circle (360° = 1 full turn).
- Everyday Focus: Terrestrial navigation, surveyor boundaries, mechanical drafting, and mathematics.
Second of Arc (arcsec / ″)
Fine Sexagesimal Division (1/3,600°)- Creator & Origin: Ptolemy's 'partes minutae secundae' (second small parts) in the 2nd-century Almagest.
- Standard Definition: Defined as exactly 1/60 of an arcminute or 1/3,600 of a degree (π/648,000 radians).
- Everyday Focus: Astrophysical parallax, Hubble pointing, double star separation, and lithography optics.
Frequently Asked Questions
Q.How many seconds of arc are in one degree?
There are exactly 3,600 seconds of arc (arcseconds) in one degree (1° = 3,600 arcsec = 3,600″).
Q.What is the reverse conversion from arcseconds to degrees?
To convert back, use the Second of Arc to Degree Converter where 1 arcsec equals 1/3,600 degree.
Q.How many arcseconds is 0.5 degrees?
0.5 degrees equals exactly 1,800 arcseconds (approximate diameter of the Moon).
Q.How many arcseconds is a full circle?
A full circle (360°) equals exactly 1,296,000 arcseconds (360 × 3,600).
Q.How do you convert degrees to arcseconds without a calculator?
Multiply the degree value by 3,600 (or multiply by 60 twice).