Angle conversion

Fast and accurate online angle conversion. Supports degrees, radians, minutes, seconds, and gradians. Real-time results with no downloads required.
°
′
″

Current calculation formulas

rad = deg * π / 180

deg = rad * 180 / π

grad = deg * 200 / 180

deg = Sexagesimal degree

rad = Radian

grad = Centesimal degree

π = 3.1415926535

Description

Convert between degrees-minutes-seconds (DMS), decimal degrees, radians, and grads. Ideal for GIS, navigation, mathematics, engineering, and astronomy. Supports real-time bidirectional conversion with high precision.

Supported Units & Conversion Factors

Unit Full Name Relation to Degree (°)
DMS Degrees-Minutes-Seconds 1° = 60′, 1′ = 60″
Example: `90° 20′ 30″ = 90 + 20/60 + 30/3600 ≈ 90.3417°`
Decimal Degree Decimal Degrees 1° = 1° (direct representation)
Rad Radian 1 rad = 180° / π ≈ 57.2958°
1° = π / 180 ≈ 0.017453 rad
Grad Grad (or Gon) 1 grad = 0.9°
1° = 100 centesimal minutes
1 grad = 100 centesimal seconds
Example: `100 grad = 90°`

Key Conversion Formulas

  • DMS → Decimal Degrees:
    Decimal° = Degrees + Minutes/60 + Seconds/3600

  • Decimal Degrees → Radians:
    rad = ° × π / 180

  • Radians → Decimal Degrees:
    ° = rad × 180 / π

  • Decimal Degrees → Grads:
    grad = ° × 100 / 90 = ° × 1.111...

  • Grads → Decimal Degrees:
    ° = grad × 0.9

Example Calculations

Example 1: DMS to Decimal Degrees

Input: `90° 20′ 30″`
Calculation:
90 + 20/60 + 30/3600 = 90 + 0.3333 + 0.008333 ≈ 90.3417°

Example 2: Decimal Degrees to Radians

Input: `90.3417°`
Calculation:
90.3417 × π / 180 ≈ 1.5768 rad

Example 3: Radians to Grads

Input: `π/2 rad ≈ 1.5708 rad`
Step 1: Convert to degrees: 1.5708 × 180 / π ≈ 90°
Step 2: Convert to grads: 90° × 100 / 90 = 100 grad
So: `π/2 rad = 100 grad`

Example 4: Grads to DMS

Input: `123.4 grad`
Step 1: Convert to degrees: 123.4 × 0.9 = 111.06°
Step 2: Convert to DMS:
- Degrees: 111°
- Minutes: 0.06 × 60 = 3.6′ → 3′ 36″
Result: 111° 3′ 36″

Example 5: Common Angles Reference Table

Degrees Radians Grads
0° 0 0
15° π/12 16.66
30° π/6 33.33
45° π/4 50
60° π/3 66.66
90° π/2 100
180° π 200
360° 2π 400

Use Cases

  • Geographic Information Systems (GIS) and map coordinates — converting latitude/longitude from DMS to decimal

  • Navigation and aviation positioning — GPS data often uses decimal degrees

  • Mathematics education and trigonometric calculations — teaching students how to convert between systems

  • Robotics motion control — angular position sensors may output in radians or degrees

  • Astronomy and timekeeping — celestial coordinates use DMS format

  • Engineering drawing and mechanical design — CAD software may require specific angle formats

Reference Standards

  • ISO 19111: Geographic information — Spatial reference systems

  • WGS84: World Geodetic System 1984 (used by GPS)

  • IEC 60050: International Electrotechnical Vocabulary

  • Textbooks: "Calculus" by James Stewart, "Surveying Principles and Applications" by Charles D. Ghilani

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Frequently asked questions

Every unit pair works both ways using mathematically inverse formulas, and results update instantly as you type — no calculate button or page reload is needed.

Free online converter for four angle formats: DMS, decimal degrees, radians and grads, with real-time bidirectional conversion and high precision.

One full circle is:

  • 360° in degrees

  • 2π radians ≈ 6.2832 rad

  • 400 grads

So:

  • 1 rad = 180° / π ≈ 57.2958°

  • 1° = π / 180 ≈ 0.017453 rad

Key values: 90° = π/2 rad, 180° = π rad.

Use radians in formulas and programming, degrees in daily work — the tool converts both instantly.

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