Introduction to Map Use

Converting between degrees:minutes:seconds and decimal degrees

 

 

Converting degrees minutes and seconds to decimal degrees

 

1.    One minute  is 1/60 degree

2.    Once second is 1/60 minute or 1/3600 degrees

3.    To convert to decimal degrees

deg

+   min /60

+    sec/3600

      decimal degrees

 

4.    Example:  45 deg 15 min 36 sec

45                                    45.0000

+    15/60              →        +    0.2500

+    36/3600                      +    0.0100

                                                    45.2600

     

Converting decimal degrees to degrees minutes and seconds

 

1.    Multiply decimal part by 60.  The whole number part of the result is the number of minutes

2.    Multiply the decimal part by 60.  The answer is the number of seconds

 

3.    example  45.26 deg

 

45 deg +

0.26 deg * 60 min/deg = 15. 6 min  →   15 min +

0.6 min  * 60 sec/min  =  36 sec

 

45.26 deg = 45 deg 15 min 36 sec

 

Doing math with degrees minutes and seconds

 

1.   if you need to subtract a larger number from a smaller one you need to borrow, remembering that 1 deg = 60 min and 1 min = 60 sec

2. if the result of adding any units is > 60 you have to carry to the next larger units

3.  examples

      4         74          96

   45 deg  15 min  36 sec

-  36 deg  34 min  52 sec

      8 deg  40 min 44 sec