aşağıdaki fonksiyonu dener misiniz?
Rad/Derece =2*π/360
Rad=Derece*(π/180)

π/180=1/ 57.2957795130823

Function HaversineHsp(lat1 As Double, lon1 As Double, lat2 As Double, lon2 As Double) As Double

    Dim R As Double

    R = 6371 ' Dünya yarıçapı km cinsinden

    

    Dim dLat As Double, dLon As Double

    dLat = (lat2 - lat1) / 57.2957795130823

    dLon = (lon2 - lon1) / 57.2957795130823

    

    Dim a As Double, c As Double

    a = Sin(dLat / 2) ^ 2 + Cos((lat1) / 57.2957795130823) * Cos((lat2) / 57.2957795130823) * Sin(dLon / 2) ^ 2

    c = 2 * Atn(Sqr(a) / Sqr(1 - a))

    

    HaversineHsp = R * c

End Function