Convert Gradians (grad) to Degrees (°)
1 gradian equals 0.9 degrees.
Gradian to Degree Converter
What Is a Gradian?
The gradian (grad), also called gon or grade, divides a right angle into exactly 100 equal parts, making a full circle equal to 400 gradians. Its exact relationship to the radian is 1 grad = π/200 rad.
Introduced during the French Revolution (1790s) as part of the metric reform, the gradian was designed to decimalize angle measurement. While it never replaced degrees globally, it remains the standard angular unit in continental European surveying, geodesy, and cadastral systems — especially in France, Belgium, Germany, and Scandinavia.
Key equivalences: 100 grad = 90°; 200 grad = 180°; 400 grad = 360°.
What Is a Degree?
The degree (°) is a non-SI unit of plane angle defined as exactly 1/360 of a full rotation. It is accepted for use with the SI due to its importance in navigation, surveying, engineering, and astronomy.
The 360-degree circle originates from ancient Babylonian astronomy and remains the dominant angular unit worldwide — used in compasses, protractors, GPS coordinates, and virtually every consumer application involving angles.
Key equivalences: 1° = π/180 rad = 60′ = 3,600″ = 10/9 grad.
Gradians to Degrees Formula
The conversion factor is exact:
degrees = gradians × 9/10 exact
This comes from the ratio: 360° / 400 grad = 9/10 = 0.9. So 1 gradian = exactly 0.9 degrees.
Worked Example
Convert a European survey bearing of 150 grad to degrees:
- Multiply: 150 × 0.9 = 135°
So 150 gradians = exactly 135°. Multiples of 10 grad always convert to clean degree values ending in whole or half degrees.
Quick Estimation
For mental math, subtract 10% from the gradian value. Example: 250 grad − 10% = 250 − 25 = 225° (exact: 225°). This works perfectly because the factor is exactly 0.9.
Common Conversions at a Glance
| Gradians | Degrees |
|---|---|
| 1 grad | 0.9° |
| 50 grad | 45° |
| 100 grad (right angle) | 90° |
| 150 grad | 135° |
| 200 grad (straight) | 180° |
| 300 grad | 270° |
| 400 grad (full circle) | 360° |
Which Is Bigger: Gradian or Degree?
A degree is 1.11 times larger than a gradian — or equivalently, a gradian is 90% of a degree. These are the most similar-sized angular units across the two systems. The difference is subtle: 100 grad vs 90° for a right angle — the gradian is simply a slightly finer subdivision.
When You Need This Conversion
- Importing European survey data: Theodolite readings and total station exports from France, Germany, or Scandinavia use gradians. Converting to degrees is needed for GIS software that defaults to degrees or for international collaboration.
- CAD interoperability: Some European CAD systems use centesimal angles (gradians). Importing files into degree-based systems (AutoCAD, SolidWorks) requires conversion.
- Scientific calculator mode: Calculators in GRAD mode display results in gradians. Converting to DEG mode for reporting or further calculations is a daily task for European surveyors.
- French cadastral records: Property boundary angles in the French land registry are recorded in gradians. Real estate transactions involving French properties require conversion to degrees for international documentation.
Frequently Asked Questions
How many degrees are in one gradian?
Exactly 0.9 degrees. The ratio 360°/400 grad = 9/10 is exact by definition. The inverse: 1° = 10/9 grad ≈ 1.1111 grad.
What is the difference between gradians, gons, and grades?
They are different names for the same unit. "Gradian" is the ISO standard name, "gon" is used in German (DIN) and Scandinavian standards, "grade" is the French term. All mean 1/400 of a circle. Calculators label it "GRA", "GRAD", or "G".
Why were gradians invented?
Created during the French Revolution (1790s) to decimalize angles — 100 grad per right angle makes percentages and mental math simpler than 90°. A half right angle is 50 grad (not 45°), a tenth is 10 grad (not 9°).
Which countries still use gradians?
France, Germany, Switzerland, Belgium, Sweden, and other European countries use gradians in professional surveying. European theodolites default to grad mode. Degrees dominate everyday use, but surveyors and civil engineers work daily with gradians.
What is the relationship between gradians and slope percentage?
For small angles, 1 grad ≈ 1.57% slope (since tan(1 grad) ≈ 0.01571). This near-linear relationship is why gradians are preferred in road and railway design — slope percentages map almost directly to gradian values.
Common Gradian to Degree Conversions
| Gradian | Degree | Actions |
|---|---|---|
| 0 gradians | 0 degrees | |
| 50 gradians | 45 degrees | |
| 100 gradians | 90 degrees |
| Gradian | Degree | Actions |
|---|---|---|
| 200 gradians | 180 degrees | |
| 400 gradians | 360 degrees |
Gradians to degrees Conversion Table
Reference table with common gradians to degrees conversions. All values calculated with high precision.
Gradians to Degrees Table
10 to 1000000
Degrees to Gradians Table
0.0001 to 12
Degrees to Gradians Table
1 to 100000
Looking for the reverse? Convert Degree to Gradian
Related Angle Converters
Explore other angle conversion tools:
Related in other categories:
- Hertz to RPM — 1 Hz = 2π rad/s — angular frequency