Garmin Coordinate Formats Explained: DD vs DDM vs DMS

Garmin GPS devices support multiple coordinate formats. Understanding the differences helps you choose the right format for your navigation needs and ensures accurate waypoint entry.

The Three Main Formats

1. Decimal Degrees (DD)

Format: 54.942497, 23.909127

• Pros: Simple, used by Google Maps, easy for digital mapping
• Cons: Hard to enter manually on GPS devices
• Best for: Online mapping, smartphone apps, data analysis

2. Degrees Decimal Minutes (DDM)

Format: N 54° 56.550' E 023° 54.548'

• Pros: Easier manual entry, good precision, Garmin default
• Cons: Requires hemisphere notation (N/S, E/W)
• Best for: Garmin GPS devices, marine navigation, field work

3. Degrees Minutes Seconds (DMS)

Format: N 54° 56' 33.0" E 023° 54' 32.9"

• Pros: Traditional navigation format, very precise
• Cons: Most complex to enter and calculate
• Best for: Surveying, aviation, traditional navigation

Why Garmin Prefers DDM

Most Garmin devices default to DDM format because:

1. Easier manual entry - Only need degrees and decimal minutes
2. Good precision - Accurate to within a few meters
3. Readable on small screens - Compact yet clear format
4. Industry standard - Common in marine and outdoor navigation

Converting Between Formats

DD to DDM (Most Common)

Example: 54.942497 → N 54° 56.550'

1. Degrees = whole number (54)
2. Minutes = decimal × 60 (0.942497 × 60 = 56.550)
3. Add hemisphere (N for positive latitude)

DDM to DD

Example: N 54° 56.550' → 54.942497

1. Take degrees (54)
2. Convert minutes to decimal (56.550 ÷ 60 = 0.9425)
3. Add together (54 + 0.9425 = 54.9425)

DMS to DDM

Example: N 54° 56' 33.0" → N 54° 56.550'

1. Keep degrees (54)
2. Convert seconds to decimal minutes (33.0 ÷ 60 = 0.550)
3. Add to minutes (56 + 0.550 = 56.550)

Setting Your Garmin Format

eTrex Series

1. Go to Setup → System → GPS 2. Select Position Format 3. Choose hddd°mm.mmm' (DDM format)

GPSMAP Series

1. Press Setup → System → GPS 2. Select Position Format 3. Choose hddd°mm.mmm' (DDM format)

Fenix/Forerunner Series

1. Hold Menu → System → GPS 2. Select Position Format 3. Choose hddd°mm.mmm' (DDM format)

Which Format Should You Use?

• For Garmin devices: DDM (hddd°mm.mmm')
• For Google Maps sharing: DD (decimal degrees)
• For traditional navigation: DMS (degrees, minutes, seconds)
• For data interchange: DD (most universally supported)

Quick Reference

Format	Example	Use Case
DD	54.942497, 23.909127	Online maps, apps
DDM	N 54° 56.550' E 023° 54.548'	Garmin GPS devices
DMS	N 54° 56' 33.0" E 023° 54' 32.9"	Traditional navigation

Ready to convert your coordinates? Try our free converter to instantly convert between any of these formats for your Garmin device.

Need device-specific help? Check out our guide on entering coordinates on Garmin eTrex 32x.