Gradian (grad) - Unit Information & Conversion

Symbol:grad
Plural:gradians
Category:Angle

🔄 Quick Convert Gradian

What is a Gradian?

Gradian (also gon or grad) is 1/400 of a full circle, designed for decimal angle measurements. 100 gradians = 90 degrees. Widely used in European surveying, civil engineering, and construction for easier calculations.

History of the Gradian

Created during French Revolution (1795) as part of metric system. Designed to replace degrees with decimal-friendly unit. Still standard in many European countries for surveying and engineering work.

Quick Answer

What is a Gradian? A gradian (also called gon or grad) is 1/400th of a full circle. 100 gradians = 90° (right angle), 400 gradians = 360° (full circle). Designed for decimal convenience in surveying and engineering. Use our angle converter for instant conversions.

Definition

1 gradian = 1/400 of a full circle = 0.9 degrees = 0.01571 radians

Key conversions:

  • 100 gradians = 90 degrees (right angle)
  • 200 gradians = 180 degrees (straight angle)
  • 400 gradians = 360 degrees (full circle)
  • 1 gradian = 0.9° = π/200 radians

Symbols: grad, gon, or superscript "g" (e.g., 100ᵍ)

Common Uses

Surveying: Primary angle unit in France, Germany, Switzerland, and Scandinavia for land surveys. Civil Engineering: Building construction, road design, slope measurements in Europe. Military: Artillery calculations and targeting in European armed forces. Geodesy: Precise Earth measurements and coordinate systems in metric countries.

Real-World Examples

European Construction

  • Building foundations: Right angles measured as 100 gradians
  • Road curves: Highway banking angles specified in gradians
  • Bridge design: Structural angles calculated in gradians for simplicity
  • Tunnel boring: Alignment measured in gradians for precision

Surveying Instruments

  • Theodolites: Many European models display gradians as default
  • Total stations: Often switchable between degrees, gradians, and mils
  • Digital levels: Construction lasers with gradian readouts
  • GPS receivers: Some European units support gradian coordinates

Calculator Applications

  • Scientific calculators: "GRAD" mode (400 gradians = full circle)
  • Casio calculators: Marked with "G" or "GRAD" for gradian mode
  • TI calculators: Mode switch between Degree, Radian, Gradian
  • Engineering software: AutoCAD, QGIS support gradian input in European versions

Slope and Gradient Measurements

  • Ski slopes: Sometimes rated in gradians (25 gradians = moderate slope)
  • Railway grades: Track inclines measured in gradians
  • Wheelchair ramps: Accessibility slopes specified in gradians
  • Drainage systems: Pipe slopes calculated in gradians

Gradian Conversion Formulas

To Degree:

1 grad = 0.9 °
Example: 5 gradians = 4.5 degrees

To Radian:

1 grad = 0.015708 rad
Example: 5 gradians = 0.07854 radians

To Arcminute:

1 grad = 54 ′
Example: 5 gradians = 270 arcminutes

To Arcsecond:

1 grad = 3240 ″
Example: 5 gradians = 16200 arcseconds

To Turn:

1 grad = 0.0025 turn
Example: 5 gradians = 0.0125 turns

To Revolution:

1 grad = 0.0025 rev
Example: 5 gradians = 0.0125 revolutions

To Quadrant:

1 grad = 0.01 quad
Example: 5 gradians = 0.05 quadrants

To Gon:

1 grad = 1 gon
Example: 5 gradians = 5 gons

To Mil:

1 grad = 16 mil
Example: 5 gradians = 80 mils

Frequently Asked Questions

Formula: Degrees = Gradians × 0.9 (or Gradians × 9/10) Examples:

Convert Gradian

Need to convert Gradian to other angle units? Use our conversion tool.