One degree is 3,600 arcseconds. Star positions, telescope resolution and parallax are measured in arcseconds.
How to use the Degrees to Arcseconds Converter
- Type the number of degrees into the Degrees field. Decimals such as 0.5 are fine.
- Read the answer in Arcseconds. It updates as you type, with no button to press. The same amount is also shown in ′, rad, mrad.
- To go from arcseconds back to degrees, type into the Arcseconds field instead. Every field also has a unit menu with all 8 angle units, for example rad, grad, ′, turn, mrad.
Results update as you type, and everything is calculated in your browser.
How it works
Both units measure angle, so they are always in the same ratio: one degree equals 3,600 arcseconds. The calculator multiplies the number of degrees you type by 3,600 to give arcseconds, and when you type into the arcseconds field it divides by the same factor to give degrees. Because the ratio never changes, doubling the degrees always doubles the arcseconds, for example 2 ° is 7,200 ″.
How to convert degrees to arcseconds
- Write down the value in degrees, for example 1 °.
- Multiply by the conversion factor 3,600 (because 1 degree = 3,600 ″).
- 1 × 3,600 = 3,600 ″.
- To go back from arcseconds to degrees, divide by 3,600, or multiply by 0.00027777778.
° to ″ conversion table
| Degrees | Arcseconds | Arcseconds | Degrees |
|---|---|---|---|
| 0.001 ° | 3.6 ″ | 1 ″ | 0.00027777778 ° |
| 0.01 ° | 36 ″ | 2 ″ | 0.00055555556 ° |
| 0.1 ° | 360 ″ | 5 ″ | 0.0013888889 ° |
| 0.5 ° | 1,800 ″ | 10 ″ | 0.0027777778 ° |
| 1 ° | 3,600 ″ | 20 ″ | 0.0055555556 ° |
| 2 ° | 7,200 ″ | 50 ″ | 0.013888889 ° |
| 100 ″ | 0.027777778 ° | ||
| 1,000 ″ | 0.27777778 ° |
Angle units explained
- Degree (°)
- A degree is 1/360 of a full turn. Navigation, construction and geometry use degrees.
- Arcsecond (″)
- An arcsecond is 1/3,600 of a degree. Astronomers use arcseconds for star positions and the resolving power of telescopes.
Common mistakes to avoid
Feeding degrees into a calculator set to radians (or the reverse), and reading decimal degrees as degrees and minutes.
Formula
1 ° = 3,600 ″
1 ″ = 0.00027777778 °
″ = ° × 3,600
Worked example
Inputs: Degrees: 1 °.
Results: Arcseconds = 3,600 ″; Arcminutes = 60 ′; Radians = 0.01745329 rad; Milliradians = 17.45329252 mrad.
Frequently asked questions
How many arcseconds in a degree?
3,600.
How big is the full Moon?
About 0.5° or 1,800 arcseconds.
How do I convert degrees to arcseconds?
Multiply the number of degrees by 3,600. For example, 1 ° × 3,600 = 3,600 ″.
How do I convert arcseconds back to degrees?
Divide by 3,600 (or multiply by 0.00027777778), or simply type the value into the arcseconds field above.
What is 2 ° in arcseconds?
2 ° = 7,200 ″.
Is the degrees to arcseconds conversion exact?
Yes. The official definitions (NIST and the SI) fix 1 ° = 3,600 ″ exactly, so the only difference you may see is rounding in the last displayed digit.