Quadrant to Radian Converter

Convert quadrants to radians with our free online angle converter.

Quick Answer

1 Quadrant = 1.570796 radians

Formula: Quadrant × conversion factor = Radian

Use the calculator below for instant, accurate conversions.

Our Accuracy Guarantee

All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.

Last verified: February 2026Reviewed by: Sam Mathew, Software Engineer

Quadrant to Radian Calculator

How to Use the Quadrant to Radian Calculator:

  1. Enter the value you want to convert in the 'From' field (Quadrant).
  2. The converted value in Radian will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Angle category.
  4. Click the swap button (⇌) to reverse the conversion direction.
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How to Convert Quadrant to Radian: Step-by-Step Guide

Converting Quadrant to Radian involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

rad = quad × 1.5708

Example Calculation:

1 quad = 1.570796 rad

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Quadrant and a Radian?

1 quadrant = 1/4 of a full circle = 90 degrees = π/2 radians ≈ 1.5708 radians

Key conversions:

  • 1 quadrant = 90 degrees
  • 1 quadrant = π/2 ≈ 1.5708 radians
  • 1 quadrant = 100 gradians (or gons)
  • 4 quadrants = 360 degrees (full circle)
  • 2 quadrants = 180 degrees (straight angle)

Symbol: quad or Q (sometimes written as "right angle")

A radian is the angle subtended at the center of a circle by an arc equal in length to the radius. 1 radian ≈ 57.2958 degrees.

Key values:

  • π radians = 180°
  • 2π radians = 360°
  • 1 radian = 180/π ≈ 57.296°

Why Radians Matter

The radian is unique because it's dimensionless:

  • Definition: Arc length ÷ Radius = Angle in radians
  • Dimensionless: Ratio of two lengths (meters ÷ meters = just a number)
  • Natural for math: Calculus formulas work perfectly with radians (no messy constants)
  • SI standard: The official unit for angles in physics and engineering
  • Degrees are arbitrary: Based on Babylonian base-60 system (historical accident)

Note: The Quadrant is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Radian belongs to the imperial/US customary system.

Common Uses and Applications: quadrants vs radians

Explore the typical applications for both Quadrant (imperial/US) and Radian (imperial/US) to understand their common contexts.

Common Uses for quadrants

Coordinate Systems: Cartesian plane divided into four quadrants (I, II, III, IV). Navigation: Compass quadrants (NE, SE, SW, NW) for direction description. Astronomy: Celestial sphere divided into quadrants for star mapping. Geometry: Right angles and perpendicular measurements in construction and design.

When to Use radians

Mathematics: Required unit for calculus (derivatives, integrals of trig functions only work with radians). Physics: Angular velocity (rad/s), rotational motion, oscillations, wave propagation. Engineering: Computer graphics, robotics, signal processing, control systems. Programming: All major languages (Python, JavaScript, C++) use radians for sin(), cos(), tan().

Additional Unit Information

About Quadrant (quad)

How do I convert quadrants to degrees?

Formula: Degrees = Quadrants × 90

Examples:

  • 1 quadrant = 90°
  • 2 quadrants = 180°
  • 3 quadrants = 270°
  • 4 quadrants = 360°
  • 0.5 quadrants = 45°

Quadrants to Degrees converter →

How do I convert quadrants to radians?

Formula: Radians = Quadrants × (π/2) ≈ Quadrants × 1.5708

Examples:

  • 1 quadrant = π/2 ≈ 1.571 radians
  • 2 quadrants = π ≈ 3.142 radians
  • 3 quadrants = 3π/2 ≈ 4.712 radians
  • 4 quadrants = 2π ≈ 6.283 radians
  • 0.5 quadrants = π/4 ≈ 0.785 radians

Quadrants to Radians converter →

What are the four quadrants in a coordinate plane?

Quadrant system divides the Cartesian plane using x and y axes:

Quadrant I (First): x > 0, y > 0

  • Angles: 0° to 90° (or 0 to π/2 radians)
  • Example point: (3, 4)

Quadrant II (Second): x < 0, y > 0

  • Angles: 90° to 180° (or π/2 to π radians)
  • Example point: (-3, 4)

Quadrant III (Third): x < 0, y < 0

  • Angles: 180° to 270° (or π to 3π/2 radians)
  • Example point: (-3, -4)

Quadrant IV (Fourth): x > 0, y < 0

  • Angles: 270° to 360° (or 3π/2 to 2π radians)
  • Example point: (3, -4)

Axes: Points on x or y axes are not in any quadrant.

Why is a right angle called a quadrant?

Etymology: "Quadrant" comes from Latin "quadrans" meaning "fourth part."

Historical context:

  • A right angle is 1/4 of a full circle rotation
  • Ancient navigational instruments called "quadrants" were quarter-circle shaped
  • The term emphasizes the fractional relationship: 1 quadrant = 1/4 circle

Modern usage: While "right angle" is more common in everyday geometry, "quadrant" is still used in:

  • Coordinate systems (Quadrant I, II, III, IV)
  • Navigation and surveying
  • Astronomy and celestial mechanics
  • Mathematical analysis and calculus

The term "quadrant" emphasizes the measurement as a fraction of a circle, while "right angle" emphasizes the geometric perpendicularity (90°).

About Radian (rad)

How do I convert radians to degrees?

Formula: degrees = radians × (180/π) = radians × 57.2958

Examples:

  • 1 rad = 57.3°
  • π/2 rad = 90°
  • π rad = 180°
  • 2π rad = 360°

How many radians in 180 degrees?

180° = π radians ≈ 3.14159 radians

This is the fundamental relationship between degrees and radians.

Why use radians instead of degrees?

Mathematical simplicity: d/dx[sin(x)] = cos(x) ONLY when x is in radians. Physics advantage: Angular velocity formulas are much simpler with radians. Programming standard: All programming languages default to radians for trig functions.

Conversion Table: Quadrant to Radian

Quadrant (quad)Radian (rad)
0.50.785
11.571
1.52.356
23.142
57.854
1015.708
2539.27
5078.54
100157.08
250392.699
500785.398
1,0001,570.796

People Also Ask

How do I convert Quadrant to Radian?

To convert Quadrant to Radian, enter the value in Quadrant in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our angle converter page to convert between other units in this category.

Learn more →

What is the conversion factor from Quadrant to Radian?

The conversion factor depends on the specific relationship between Quadrant and Radian. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.

Can I convert Radian back to Quadrant?

Yes! You can easily convert Radian back to Quadrant by using the swap button (⇌) in the calculator above, or by visiting our Radian to Quadrant converter page. You can also explore other angle conversions on our category page.

Learn more →

What are common uses for Quadrant and Radian?

Quadrant and Radian are both standard units used in angle measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our angle converter for more conversion options.

For more angle conversion questions, visit our FAQ page or explore our conversion guides.

All Angle Conversions

Degree to RadianDegree to GradianDegree to ArcminuteDegree to ArcsecondDegree to TurnDegree to RevolutionDegree to QuadrantDegree to GonDegree to MilRadian to DegreeRadian to GradianRadian to ArcminuteRadian to ArcsecondRadian to TurnRadian to RevolutionRadian to QuadrantRadian to GonRadian to MilGradian to DegreeGradian to RadianGradian to ArcminuteGradian to ArcsecondGradian to TurnGradian to RevolutionGradian to QuadrantGradian to GonGradian to MilArcminute to DegreeArcminute to RadianArcminute to GradianArcminute to ArcsecondArcminute to TurnArcminute to RevolutionArcminute to QuadrantArcminute to GonArcminute to MilArcsecond to DegreeArcsecond to RadianArcsecond to GradianArcsecond to ArcminuteArcsecond to TurnArcsecond to RevolutionArcsecond to QuadrantArcsecond to GonArcsecond to MilTurn to DegreeTurn to RadianTurn to GradianTurn to ArcminuteTurn to ArcsecondTurn to RevolutionTurn to QuadrantTurn to GonTurn to MilRevolution to DegreeRevolution to RadianRevolution to GradianRevolution to ArcminuteRevolution to ArcsecondRevolution to TurnRevolution to QuadrantRevolution to GonRevolution to MilQuadrant to DegreeQuadrant to GradianQuadrant to ArcminuteQuadrant to ArcsecondQuadrant to TurnQuadrant to RevolutionQuadrant to GonQuadrant to MilGon to DegreeGon to RadianGon to GradianGon to ArcminuteGon to ArcsecondGon to TurnGon to RevolutionGon to QuadrantGon to MilMil to DegreeMil to RadianMil to GradianMil to ArcminuteMil to ArcsecondMil to TurnMil to RevolutionMil to QuadrantMil to Gon

Verified Against Authority Standards

All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.

NIST Reference on Constants, Units and Uncertainty

National Institute of Standards and TechnologyFundamental physical constants and unit conversions

BIPM SI Units

Bureau International des Poids et MesuresInternational System of Units (SI) definitions and standards

ISO 80000

International Organization for StandardizationQuantities and units international standards series

Last verified: February 19, 2026