Number conversion

DMS to decimal degrees

Convert degrees, minutes, seconds (DMS) to decimal degrees. Free online tool — no sign-up. Mobile-friendly and privacy-first. Runs locally in your browser.

Instant result

Result

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Enter values to convert.

Inputs —

Mode —

Formula —

Formulas

Core equations used by this converter.

Formuladd = d + m/60 + s/3600

iCombine degrees, minutes, and seconds with dd = d + m/60 + s/3600. Apply S/W as negative in GIS when required.

How to use

1

Enter degrees, minutes, seconds

Type integer degrees d, minutes m (0–59), and seconds s (may be decimal).

2

Apply the formula

Compute dd = d + m/60 + s/3600.

3

Read decimal degrees

Apply hemisphere sign (S/W often negative in GIS APIs).

Example conversions

Common values with formula and result.

ϟ

30° 15′ 50″

30° 15′ 50″

dd = 30 + 15/60 + 50/3600

30.263889°

ϟ

45° 30′ 0″

45° 30′ 0″

dd = 45 + 30/60 + 0

45.5°

ϟ

1° 0′ 36″

1° 0′ 36″

dd = 1 + 0 + 36/3600

1.01°

DMS to decimal degrees specification

Version 1.1.0 · Engine tested

Calculation status

Engine tested 3 published cases
Named expert review Not performed
Calculation version 1.1.0

Definition: **DMS** — degrees (°), minutes (′), seconds (″). Traditional for latitude/longitude and surveying. **Decimal degrees (DD)** — a single real number of degrees (e.g. `30.2639°`), preferred by most GIS and programming APIs.
What it calculates: Convert degrees, minutes, seconds (DMS) to decimal degrees. Formula dd = d + m/60 + s/3600. Examples, steps, and FAQ for maps and surveying.
Inputs: Degrees, minutes, seconds (DMS)
Outputs: Decimal degrees (dd)
Formula: dd = d + m/60 + s/3600
DMS → decimal degrees chart: DMS Decimal degrees
0° 30′ 0″ 0.5°
15° 0′ 0″ 15°
30° 15′ 50″ 30.263889°
45° 30′ 0″ 45.5°
90° 0′ 0″ 90°
180° 0′ 0″ 180°
Assumptions: Conversion runs locally in the browser; values are not uploaded.
Uses the formulas documented on this page.
Units: DMS → decimal degrees
Boundary conditions: Empty or invalid input yields no valid result.
Minutes should be 0–59; seconds 0–59 (decimal allowed).
Example: 30° 15′ 50″ → 30.263889°
Validation cases: 30° 15′ 50″ → 30.263889°
45° 30′ 0″ → 45.5°
1° 0′ 36″ → 1.01°
Sources: CalculatorX converter runtime
Standard unit / encoding definitions where applicable
Calculation version: 1.1.0

Background

Interpretation and common distinctions.

Use the converter tabs to switch direction when available. Results for DMS to decimal degrees update locally in your browser.

Frequently asked questions

Key distinctions behind the conversion.

How do you convert DMS to decimal degrees?

Use dd = d + m/60 + s/3600. Example: 30° 15′ 50″ → 30.263889°.

What order are minutes and seconds?

Always degrees first, then minutes (0–59), then seconds (0–59, may be decimal).

How do I convert decimal back to DMS?

Use the decimal → DMS tab or open the paired reverse converter.

Does this run online or locally?

Calculation runs locally in your browser. Values are not uploaded.