[Solved] Calculate (Find) distance between two Geographical Coordinates (Latitude and Longitude) in SQL Server

You will need to use the Geography DataType in SQL Server 2008 or higher.

DECLARE @Mumbai GEOGRAPHY = 'POINT(18.9750 72.8258)'
DECLARE @Delhi GEOGRAPHY = 'POINT(28.6100 77.2300)'

SELECT @Mumbai.STDistance(@Delhi) / 1000

You will have to remove comma and then use

DECLARE @Coordinates TABLE (Id INT, Coordinate VARCHAR(1000))

INSERT INTO @Coordinates
VALUES (1, '55.56556210072329, 9.755743105435158'),
(2, '55.53810346218259, 9.719881970906044')

SELECT CAST('POINT(' + REPLACE(Coordinate, ',', '') + ')' AS GEOGRAPHY) FROM @Coordinates

DECLARE @C1 GEOGRAPHY = (SELECT CAST('POINT(' + REPLACE(Coordinate, ',', '') + ')' AS GEOGRAPHY) FROM @Coordinates WHERE Id = 1)
DECLARE @C2 GEOGRAPHY = (SELECT CAST('POINT(' + REPLACE(Coordinate, ',', '') + ')' AS GEOGRAPHY) FROM @Coordinates WHERE Id = 2)
 
SELECT @C1.STDistance(@C2) / 1000