# wrong value from atan2 function in excel

I am trying to calculate the angle between two latitudes and longitudes but I am getting wrong result of `atan2(X,Y)` when used on Excel.

``````β = atan2(X,Y) = atan2(0.05967668696, -0.00681261948)
``````

It should be 1.68radian (96.51°) but on excel it is showing -0.113666736 (-6.512624235°)

``````β = atan2(X,Y),
``````

where, X and Y are two quantities and can be calculated as:

• X = `cos θb * sin ∆L`
• Y = `cos θa * sin θb – sin θa * cos θb * cos ∆L`

Latitude/Longitude(1): (Lat1,Lon1)= 39.099912, -94.581213

Latitude/Longitude(2): (Lat2,Lon2)= 38.627089, -90.200203

``````‘L’            be the longitude,
‘∆L=lon2-lon1’ be the difference of longitude,
‘θ’            be latitude,
‘β‘            be Bearing
``````
• Not sure if you're aware, but there is a mathematica.se - also my `atan2()` is giving me -0.11367 - so you're converting it to degrees, which you didn't indicate. – Raystafarian Aug 3 '15 at 18:04
• yes you are right, I am converting it in degree after using atan2(x,y).. – Fahadkalis Aug 3 '15 at 18:10
• that's the same formula I am using – Fahadkalis Aug 3 '15 at 18:24

1. There is nothing wrong with `atan2(X,Y)` function in Excel: the point you have specified '(0.05967668696, -0.00681261948)' lies in the fourth quadrant, i.e. its angle is really '-6.51°'.
``````  β=ATAN2(ABS(0.05967668696), ABS(-0.00681261948))