Azimuth: which way around?
In this convention, north is 0°, east 90°, south 180° and west 270°. 360° returns to north. A compass app may show magnetic rather than true north; check its setting and the convention used by your map.
Try a coordinate · no app required
Where does that direction point?
Azimuth is the bearing around the horizon. Altitude is the angle above or below it. Enter decimal degrees from a map that uses north as 0° and increases clockwise.
Explain an azimuth and altitude
Example only · not a live sky reading
30° above the horizon, towards south-east
Azimuth 135° is clockwise from north. South-east is halfway between east and south. An altitude of 30° is one-third of the angular distance from the horizon to straight overhead. This does not establish an object’s identity or visibility.
135° · nearest south-east
Bearing diagram viewed from above, not an overhead sky chart.
Use the direction in context.
In AstraScope, check the observing place and time before choosing a target. Use the map and object details to compare the surrounding pattern; a direction alone does not identify a star or guarantee a clear view.
The web tool is free. Check the App Store and app for current access, purchases, eligibility and billing terms.
The two angles answer different questions.
Altitude: how far up?
0° is the mathematical horizon, 45° is halfway up and 90° is straight overhead. Negative values point below the horizon. Trees, buildings and hills are not part of that mathematical plane.
What this cannot tell you
This is not an object search, forecast, telescope controller or navigation instrument. It does not convert right ascension and declination, compute rise times or read your phone’s sensors.
Before comparing with the sky
Why does my sky map seem reversed?
An overhead sky chart represents looking up; this bearing diagram represents looking down. East and west can therefore appear on different sides. Follow your map’s orientation instructions, not the diagram’s screen position. Work through the map-reading guide.
Does a positive altitude mean I will see the object?
No. It only puts the supplied coordinate above a mathematical horizon. Cloud, local obstructions, daylight, brightness and equipment can prevent a sighting. Read the weather guide and naked-eye checklist.
Can I use hours, degrees/minutes/seconds or coordinates from another place?
Not directly. These fields accept decimal degrees only, with azimuth clockwise from north. Use coordinates for your intended observing place and time. Do not substitute right ascension, declination or a bearing measured from south.
Method and safety
Reviewed 9 October 2026. The tool maps entered azimuth to the nearest of eight compass points and interprets altitude without refraction or horizon corrections. The exact entered bearing remains in the result.
NASA JPL’s coordinate definitions and the Stellarium User Guide explain the horizontal coordinate convention. NASA JPL’s observing exercise explains matching a map with your location and time. These are independent references, not endorsements.
Stop walking before using a screen. Never look at the Sun through unprotected eyes or optical equipment, and never point a laser at an aircraft or an unidentified light.