Decimal Degrees vs Degrees Minutes Seconds (DMS): Complete Guide

GPS coordinates can be written in multiple formats. The two most common are Decimal Degrees (DD) and Degrees, Minutes, Seconds (DMS). Understanding both is essential when working with maps, GPS devices, or geographic data.

The Two Main Formats

Decimal Degrees (DD)

40.7128° N, 74.0060° W
or simply
40.7128, -74.0060

This modern format expresses coordinates as decimal numbers. It's the default for most digital applications, including Google Maps, GPS devices, and mobile apps.

Key characteristics:

• Positive values = North (latitude) or East (longitude)
• Negative values = South (latitude) or West (longitude)
• Typically shows 4-6 decimal places
• Easy for computers to process

Degrees, Minutes, Seconds (DMS)

40° 42' 46.08" N, 74° 0' 21.6" W

This traditional format divides each degree into 60 minutes, and each minute into 60 seconds—similar to how we measure time.

Key characteristics:

• Uses ° for degrees, ' for minutes, " for seconds
• Always includes cardinal direction (N, S, E, W)
• Traditional format used in aviation, maritime, surveying
• More intuitive for humans to read on paper maps

Quick Comparison

Converting DMS to Decimal Degrees

Formula:

DD = Degrees + (Minutes ÷ 60) + (Seconds ÷ 3600)

Example: Convert 40° 42' 46" N to decimal

1. Start with degrees: 40
2. Add minutes ÷ 60: 42 ÷ 60 = 0.7
3. Add seconds ÷ 3600: 46 ÷ 3600 = 0.0128
4. Total: 40 + 0.7 + 0.0128 = 40.7128

Since it's North latitude, the value stays positive. For South or West, make it negative.

Converting Decimal Degrees to DMS

Example: Convert 40.7128 to DMS

1. The whole number is degrees: 40°
2. Multiply decimal by 60: 0.7128 × 60 = 42.768
3. Whole number is minutes: 42'
4. Multiply remaining decimal by 60: 0.768 × 60 = 46.08
5. Result is seconds: 46.08"

Final answer: 40° 42' 46.08"

Precision Comparison

How much precision do you need?

For most purposes, 5 decimal places provides sufficient accuracy.

Which Format Should You Use?

Use Decimal Degrees When:

• Working with Google Maps, Apple Maps, GPS apps
• Programming or working with databases
• Sharing coordinates digitally
• Calculating distances or working with math

Use DMS When:

• Working with aviation or maritime charts
• Using paper topographic maps
• Surveying or professional cartography
• Historical or scientific documentation

Common Mistakes to Avoid

1. Mixing Up Latitude and Longitude

Latitude always comes first. Remember: "Lat comes before Long" alphabetically.

2. Wrong Signs for Negative Values

• West of Greenwich = negative longitude
• South of equator = negative latitude

3. Using Commas as Decimal Points

Some countries use commas (40,7128) but GPS systems expect periods (40.7128).

4. Confusing Minutes with Decimal

40° 42.77' is NOT the same as 40° 42' 77"

• 42.77 minutes = 42 minutes, 46.2 seconds
• 42' 77" is invalid (seconds max out at 60)

Finding Coordinates in Both Formats

Our GPS Coordinates tool displays your location in both formats automatically:

1. Visit the page and allow location access
2. See your coordinates in decimal and DMS
3. Copy whichever format you need

Entering Coordinates

Most mapping services accept both formats:

Google Maps accepts:

• 40.7128, -74.0060 (decimal)
• 40°42'46"N 74°0'22"W (DMS)

Just paste either format into the search bar.

Related Articles:

• How to Find Your Latitude and Longitude
• How to Enter Coordinates into Google Maps
• GPS vs IP Location: What's the Difference?