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DDM to DMS Converter

Converts coordinates from degrees decimal minutes to degrees minutes seconds.

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How to use this calculator
DDM value

Overrides the boxes, e.g. 40°26.7717′

Display only — the exact value is carried, and a rounded 60 carries into the next unit.

Result

Enter a value to see it converted.

More decimals describe the notation more finely; they do not make the coordinate more accurate than the measurement behind it.

Which way is positive
Teaching diagram
Which way is positiveA globe outline split by the equator and the prime meridian: north and east are positive, south and west negative.N +S −E +W −Latitude: N +, S −Longitude: E +, W −−33.8 (latitude) = 33.8° S−0° 30′ = 0° 30′ S−33.8 N says two things:you choose which to trust
North and east are positive; south and west are negative. The sign (or letter) applies once to the whole angle, so −0° 30′ is 0° 30′ S on latitude — the hemisphere survives a zero degree value.

How the method works

A fixed worked example to explain the method — it is not your result.

One angle, three representations
Illustrative method
One angle, three representationsThe same angle written as degrees-minutes-seconds, degrees and decimal minutes, and decimal degrees, with the conversion between each.DMS40°26′46.302″DDM40°26.7717′DD40.446195°26′ + 46.302″ ÷ 60= 26.7717′40° + 26.7717′ ÷ 60= 40.446195°
40° 26′ 46.302″ = 40° 26.7717′ = 40.446195°. Seconds ÷ 60 join the minutes; minutes ÷ 60 join the degrees. The sign (or hemisphere letter) applies once to the whole angle.

Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.

How to use this calculator

  1. Choose Single angle, Latitude & longitude, or Batch / CSV, and the angle type.
  2. Type degrees and decimal minutes (or paste the value, e.g. 40°26.7717′ N) and pick the hemisphere or sign.
  3. Choose second decimals (0–8). Read the DMS, with the decimal degrees beside it, and copy what you need.

How it works

Whole minutes = ⌊decimal minutes⌋; seconds = (decimal minutes − whole minutes) × 60. Degrees stay the same.

The value is exact until the single display rounding, and a rounded 60 carries upwards: 12° 59.999999′ at whole seconds is 13° 0′ 0″.

Decimal minutes must be at least 0 and less than 60; trailing letters or stray characters are refused, not quietly cut off.

The hemisphere belongs to the whole value, so −0° 30.5′ of latitude is 0° 30′ 30″ S.

Worked example

40° 26.7717′. = 40° 26′ 46.302″ (0.7717 × 60 = 46.302 seconds) = 40.446195°.

Common mistakes

  • Reading 26.5′ as 26′ 50″ — it is 26′ 30″.
  • Entering 60 decimal minutes instead of adding a degree.
  • Losing the south hemisphere on a value under one degree.

Frequently asked questions

What's the difference between DMS and DDM?

DMS splits the fraction of a degree into minutes and seconds; DDM keeps minutes with a decimal and has no seconds. GPS units often use DDM.

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Cite this tool

Zerdly. (2026). DDM to DMS Converter. Retrieved from https://www.zerdly.com/tools/ddm-to-dms-converter/

Tip: Enter any known values to calculate the remaining results.

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