Zerdly

DDM to Decimal Degrees Converter

Degrees and decimal minutes — including compact DDMM.mmmm — to signed decimal degrees, for single values, pairs or a CSV list.

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How to use this calculator

Inputs

Degrees and decimal minutes (or compact DDMM.mmmm) to signed decimal degrees — single values, pairs or a CSV list.

Degree, minute (°/′ or deg/min) and hemisphere letter or sign. Minutes must be at least 0 and less than 60. A minus with N/E is a conflict; a minus with S/W is applied once.

Extra printed digits do not make the input more accurate.

More options

Enter the values and press Calculate.

Or load an example to see a worked result.

Whole degrees + fraction of a degree
Illustrative
Whole degrees + fraction of a degreeFor each value, a bar for one degree split at the fractional part, with the fraction shown as minutes out of 60.Example: −32° + 30.0000′ S0′15′30′45′60′0.5°
Example: 32 whole degrees + 0.5° (= 30.0000′ of 60′), S.
Calculate first: a stale result cannot be exported.

Batch from CSV

One row per calculation, with a header row. Values use the units currently selected in the form above. Up to 10,000 rows; nothing is uploaded.

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 one latitude/longitude, a coordinate pair, a generic angle or a CSV list.
  2. Type degrees and decimal minutes with a hemisphere letter or sign (32° 30.000′ S, or 32deg30.000minS), or choose the compact DDMM.mmmm format (3157.0000S).
  3. For pairs, state the order — it is never guessed.
  4. Choose 0–10 decimal places for the result.

How it works

DD = sign × (degrees + minutes ÷ 60). The sign or hemisphere applies to the whole angle: 0° 30′ S is −0.5, not +0.5.

Minutes must be at least 0 and below 60; at 90° latitude or 180° longitude they must be 0. A minus with N or E is a conflict; a minus with S or W is applied once.

Arithmetic is exact; rounding happens once, on display. A plain number such as 3259.123 is read as compact DDM only when you choose that format.

Worked example

32° 30.000′ S and 40° 26.767′ N. −(32 + 30 ÷ 60) = −32.5. 40 + 26.767 ÷ 60 = 40.4461166667. Compact 3157.0000S is −(31 + 57 ÷ 60) = −31.95. 151° 12′ E is 151.2.

Frequently asked questions

Does converting change the position?

No. Notation changes only how the angle is written — not the datum, epoch or height.

What happens to bad rows in a list?

They go into a separate error report with the reason; nothing is dropped silently.

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Cite this tool

Zerdly. (2026). DDM to Decimal Degrees Converter. Retrieved from https://www.zerdly.com/tools/degrees-decimal-minutes-ddm-to-dd-converter/

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

Designed to run locally in your browser. Tool inputs are not intentionally stored by Zerdly unless stated otherwise.