Decimal Degrees vs DMS Explained

You're trying to enter coordinates from an old property deed into a modern GPS app, but the app rejects them. It's the classic clash between analog maps and digital tech: DMS vs Decimal Degrees.

Two Ways to Write the Same Thing

Imagine measuring time. You can say "It's 1 hour and 30 minutes" or you can say "It's 1.5 hours." It's the exact same amount of time, just formatted differently. Coordinates work the same way.

DMS (Degrees, Minutes, Seconds) is the old way: 40 41' 21" N. Like a clock, the degrees are divided into 60 minutes, and the minutes into 60 seconds.

Decimal Degrees (DD) is the new way: 40.6892. It converts the whole thing into a single, clean decimal number that computers love.

Why You Must Know the Difference

If a 911 dispatcher asks for your coordinates, and you read a DMS coordinate but they type it into their system as a Decimal coordinate, the rescue helicopter will fly to the completely wrong location. Most modern apps (Google Maps, Uber, GPS trackers) demand Decimal Degrees.

Example: The Formatting Difference

Let's look at the exact same location in Los Angeles:

  • DMS Format: 34 03' 08" N, 118 14' 37" W
  • Decimal Format: 34.0522, -118.2437

Notice the negative sign in the Decimal format! Because it doesn't use "W" for West, it uses a minus sign to tell the computer which direction to go.

Need to convert coordinates instantly? Use our free tool below.

Convert DMS to Decimal

Easily translate old map coordinates into Google Maps format.

Common Formatting Mistakes

  1. Mixing Formats (DMM): There is a third, sneaky format called Degrees Decimal Minutes (DMM), which looks like 40 41.35'. Boaters use this. Don't confuse it with true Decimal Degrees.
  2. Dropping the Negative Sign: If you convert a US coordinate to decimal and forget the negative sign on the longitude, your point will end up in China instead of California.

Frequently Asked Questions

Which format is more accurate?

Neither! They are mathematically identical. However, to match the precision of 1 arc-second (which is about 30 meters), you need to use at least 4 decimal places in the Decimal Degree format.

How do I type the degree symbol ()?

On Windows, hold Alt and type 0176 on the number pad. On Mac, press Option+Shift+8. Or, you can just use our conversion tool which auto-detects the format even if you leave the symbol out.