How many radians in 180 degrees?

180 degrees equals π radians (approximately 3.14159 rad).

What is 90 degrees in radians?

90° equals π/2 radians (approximately 1.5708 rad).

How do I convert radians to degrees?

Multiply the radian value by 180/π. For example, π radians = 180°.

Is this converter accurate?

Yes, it uses JavaScript's Math.PI for maximum precision, with adjustable decimal places.

Yes. All conversions happen locally in your browser. No data is sent anywhere.

Do I need to sign up?

No signup or registration is required. The tool is completely free.

Degrees to Radians Converter — Free Conversion

The Degrees to Radians Converter converts between degrees and radians — essential for math, physics, engineering, and game development. All calculations happen locally in your browser. Whether you are solving trigonometry problems, programming game physics, or studying calculus, converting between degrees and radians is a fundamental skill. This converter handles both directions instantly with adjustable precision, so you never need to remember the formula.

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How to Use

1
Enter a value: Type the degree or radian value in the "From" field.
2
Select direction: Choose ° or rad as your starting unit.
3
Read result: Converted value appears instantly. Use ↕ to swap.

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The Formula

deg to rad

value × (π/180) = radians

rad to deg

value × (180/π) = degrees

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Real-World Applications

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Trigonometry
90° = π/2 rad. Standard for sine, cosine, and tangent.

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Game Dev
Rotation & animation use radians. Essential for engine math.

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Physics
Wave motion and rotational mechanics use radians.

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Calculus
Derivatives of trig functions require radian measure.

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How the Conversion Works

The converter uses JavaScript Math.PI constant for high-precision calculations. To convert degrees to radians, the value is multiplied by (Math.PI / 180). For radians to degrees, the value is multiplied by (180 / Math.PI). The formula box below the result shows exactly which calculation was used, helping you learn the conversion process. The precision selector lets you choose between 2 and 8 decimal places.

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Quick Reference Tips

Bookmark the common angles: 0=0, 30=/6, 45=/4, 60=/3, 90=/2, 180=, 270=3/2, 360=2. Use the swap button () to quickly reverse your conversion. For school assignments, set precision to 4 decimal places to match standard textbook formatting.

Frequently Asked Questions

How do I convert degrees to radians?

Multiply degrees by π/180. Example: 90° × π/180 = π/2 rad ≈ 1.5708 rad.

What is 1 radian in degrees?

1 radian ≈ 57.2958°.

What are common angle conversions?

0°=0, 30°=π/6, 45°=π/4, 60°=π/3, 90°=π/2, 180°=π, 270°=3π/2, 360°=2π rad.

Is my data safe?

Yes. All calculations happen locally in your browser. No data is sent anywhere.

Why do we use radians instead of degrees?

Radians are the natural unit for angular measurement in mathematics. Many calculus formulas are simpler when angles are measured in radians.

What is the formula for degrees to radians?

Multiply degrees by /180. For example, 45 = 45 /180 = /4 radians.

How accurate is this converter?

Uses JavaScript Math.PI for maximum precision. You can adjust decimal places from 2 to 8.

🔒 Privacy Note: All calculations happen locally in your browser. No data is sent or stored.

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