Hours, minutes, seconds to decimal hours
Type a value in RA to get it in h instantly.
18.62h
That's about the same as Vega.
Convert the other way: h to RA
What it means
Where is that on the sky?
Star positions are J2000. Right ascension minutes and seconds are time units, 15 times larger than arcminutes and arcseconds.
The math
How to convert RA to h
degrees = (h + m/60 + s/3600) × 15; hours = degrees ÷ 15.
Example: 18h 36m 56.2s RA = 18.6156 h.
Every unit
That position in every unit
Tables
RA to h conversion table
| RA | h |
|---|---|
| 0h 00m 00.0s RA | 0 h |
| 1h 00m 00.0s RA | 1 h |
| 2h 00m 00.0s RA | 2 h |
| 3h 00m 00.0s RA | 3 h |
| 4h 00m 00.0s RA | 4 h |
| 5h 00m 00.0s RA | 5 h |
| 6h 00m 00.0s RA | 6 h |
| 8h 00m 00.0s RA | 8 h |
| 10h 00m 00.0s RA | 10 h |
| 12h 00m 00.0s RA | 12 h |
| 14h 00m 00.0s RA | 14 h |
| 16h 00m 00.0s RA | 16 h |
| 18h 00m 00.0s RA | 18 h |
| 20h 00m 00.0s RA | 20 h |
| 22h 00m 00.0s RA | 22 h |
| 23h 00m 00.0s RA | 23 h |
h to RA conversion table
| h | RA |
|---|---|
| 0 h | 0h 00m 00.0s RA |
| 1 h | 1h 00m 00.0s RA |
| 2 h | 2h 00m 00.0s RA |
| 3 h | 3h 00m 00.0s RA |
| 4 h | 4h 00m 00.0s RA |
| 5 h | 5h 00m 00.0s RA |
| 6 h | 6h 00m 00.0s RA |
| 8 h | 8h 00m 00.0s RA |
| 10 h | 10h 00m 00.0s RA |
| 12 h | 12h 00m 00.0s RA |
| 14 h | 14h 00m 00.0s RA |
| 16 h | 16h 00m 00.0s RA |
| 18 h | 18h 00m 00.0s RA |
| 20 h | 20h 00m 00.0s RA |
| 22 h | 22h 00m 00.0s RA |
| 23 h | 23h 00m 00.0s RA |
Quick answers
Quick answers
- How many h is 1h 00m 00.0s RA?
- 1h 00m 00.0s RA is 1 h.
- How many h is 10h 00m 00.0s RA?
- 10h 00m 00.0s RA is 10 h.
- How many h is 18h 36m 56.2s RA?
- 18h 36m 56.2s RA is 18.6156 h.
The units
About these units
Hours, minutes, seconds (RA)
Right ascension written 5h 35m 17.2s.
Decimal hours (h)
Right ascension in decimal hours.
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