Arcseconds (″)
The arcsecond is 1/60 of an arcminute, 1/3,600 of a degree.
Convert arcseconds to any angle unit
1 arcsecond = 0.000277777778 degrees
Quick facts
1 arcsecond in other units
| Degrees | 0.000277777778 ° |
| Radians | 0.000004848137 rad |
| Arcminutes | 0.01666666667 ′ |
| Gradians | 0.000308641975 grad |
| Milliradians | 0.004848136811 mrad |
| Turns | 7.7160494 × 10-7 tr |
| NATO mils | 0.004938271605 mil |
What is a arcsecond?
The arcsecond is 1/60 of an arcminute, 1/3,600 of a degree. It is the unit of astronomical parallax and of the sharpness of telescope images; a parsec is defined by one arcsecond of parallax.
Where the arcsecond sits among angle units
The arcsecond is number 4 of 24 on our scale of angle units, ordered from smallest to largest.
Arcseconds in real life
- A US quarter seen from 5 km subtends about 1 arcsecond
- The Hubble telescope resolves about 0.05 arcseconds
Top arcsecond conversions
Common amounts of arcseconds
Convert arcseconds to all 23 other units
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Frequently asked questions
What is a arcsecond?
The arcsecond is 1/60 of an arcminute, 1/3,600 of a degree.
How is the arcsecond defined?
1/3,600 of a degree.
How many degrees are in a arcsecond?
One arcsecond equals 0.000277777778 degrees.
How many radians are in a arcsecond?
One arcsecond equals 0.000004848137 radians.
How many arcminutes are in a arcsecond?
One arcsecond equals 0.01666666667 arcminutes.