How to Convert a Decimal Latitude

Longitude and latitude are angular measurements used to identify a specific location on the surface of the earth. This angular measurement can be a decimal number, but the most common form is degrees, minutes and seconds, or DMS. When performing mathematical calculations, the decimal form is much easier to work with, but because the DMS form allows for more precision, it is preferred in navigation applications. The conversion from one to the other is simple, but you need to pay attention to the details in your calculations to get an accurate answer.

Things You'll Need

• Calculator

Instructions

1. Separate the whole and decimal parts of the latitude. The Tropic of Cancer is the line of latitude at 23.4394444 degrees.

   Whole portion: 23 degrees
   Decimal portion: 0.4394444

2. Convert the decimal portion to minutes and separate the whole and decimal parts as before. The conversion factor is 60.

   0.4394 x 60 = 26.36664
   Whole portion: 26
   Decimal portion: 0.36664

3. Convert the decimal portion from the minutes calculation to seconds. The conversion factor is 60.

   0.36664 x 60 = 22

4. Combine the whole portion of the degrees, the whole portion of the minutes and the final value for the seconds to get the latitude measurement in its proper format: 23 degrees, 26 minutes, 22 seconds.

Tips & Warnings

• When converting a DMS value to a decimal value, simply reverse the step, dividing by 60 instead of multiplying.

References

• Indiana University-Purdue University: Latitude - Longitude Math
• Science Daily; Tropic of Cancer