Recognize the parts of the DMS coordinate. For example, a coordinate reading 45°23'19"N means the location is at latitude 45 degrees, 23 minutes and 19 seconds North.
Convert the minutes into seconds. Multiply 23 by 60 to get 1380 (23 x 60 = 1380).
Add the number of seconds in the DMS coordinate with the resultant number of seconds from Step 2. In this case, 19 plus 1380 renders 1399 (19 + 1380 = 1399).
Divide the number of seconds by 3600 (since there are 3600 seconds in an hour). So, 1399 divided by 3600 equals 0.38861 repeating (1399 / 3600 = 0.38861¯).
Add the fractional amount to the whole degree amount. In this instance, 45 plus 0.38861, which yields 45.38861° (45 + 0.38861 = 45.38861). This is the decimal degree version of the coordinate.
