Convert Degrees Minutes Seconds to Degrees Decimal Minutes Calculator

This calculator converts angles from degrees, minutes, and seconds (DMS) format to degrees and decimal minutes (DDM). It's useful for navigation, surveying, and any application requiring precise angle measurements.

How to Use This Calculator

To convert degrees, minutes, and seconds to degrees and decimal minutes:

Enter the degrees value in the first field
Enter the minutes value in the second field (0-59)
Enter the seconds value in the third field (0-59.999)
Click "Calculate" to see the result
Use the "Reset" button to clear all fields

Note

The calculator handles both positive and negative angle values. For southern latitudes or western longitudes, use negative values.

Formula Explained

Conversion Formula

Degrees Decimal Minutes (DDM) = Degrees + (Minutes + (Seconds / 60)) / 60

This formula converts the seconds to minutes by dividing by 60, adds them to the minutes, then converts the combined minutes to decimal minutes by dividing by 60, and finally adds this to the original degrees.

For example, converting 45° 30' 15" to DDM:

Convert seconds to minutes: 15" ÷ 60 = 0.25'
Add to minutes: 30' + 0.25' = 30.25'
Convert minutes to decimal minutes: 30.25' ÷ 60 = 0.5042°
Add to degrees: 45° + 0.5042° = 45.5042° DDM

Worked Examples

DMS Format	DDM Result	Explanation
30° 15' 30"	30.2583°	30 + (15 + (30/60))/60 = 30.2583
5° 30' 0"	5.5°	5 + (30 + (0/60))/60 = 5.5
12° 45' 15"	12.7542°	12 + (45 + (15/60))/60 ≈ 12.7542

Frequently Asked Questions

What is the difference between DMS and DDM?: DMS (Degrees Minutes Seconds) uses separate fields for degrees, minutes, and seconds. DDM (Degrees Decimal Minutes) combines minutes and seconds into a single decimal value after the degrees.
When should I use DMS vs DDM?: DMS is often used in older navigation systems and maps. DDM is more common in modern GPS devices and digital mapping software.
Can I convert DDM back to DMS?: Yes, you can reverse the calculation by separating the decimal part of the degrees into minutes and seconds.
What if my seconds value has decimals?: The calculator accepts decimal seconds (e.g., 30.5 seconds). These are converted proportionally in the calculation.