Angle Converter
Convert degrees, radians, gradians, arcminutes, arcseconds, and revolutions.
Result
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Base Unit
Relative Value
*Diagram shows values relative to the selected base unit (Degree).
Unit Information
What are Degrees (°)?
A degree (symbol: °) is the most common unit for measuring angles, where a full circle is divided into 360 degrees. Each degree is further subdivided into 60 arcminutes, and each arcminute into 60 arcseconds. Degrees are widely used in everyday life, construction, and navigation.
What are Radians (rad)?
A radian (symbol: rad) is the SI unit for measuring angles. One radian is the angle subtended at the center of a circle by an arc that is equal in length to the radius of the circle. A full circle is 2π radians (approximately 6.283 radians). Radians are extensively used in mathematics, physics, and engineering, particularly in calculus and for describing rotational motion.
What are Gradians (Gon)?
A gradian (symbol: grad), also known as a gon, is a unit of angle where a right angle is 100 gradians and a full circle is 400 gradians. This unit was created to decimalize the angle, making some calculations in surveying simpler.
What are Milliradians (mrad)?
A milliradian (symbol: mrad or mil) is one-thousandth of a radian. It's a useful unit for very small angles and is widely used in optics, long-range shooting, and military applications for range estimation and targeting.
What are Arcminutes (′) and Arcseconds (″)?
An arcminute is 1/60th of a degree, and an arcsecond is 1/60th of an arcminute (or 1/3600th of a degree). These units are used in fields that require high precision angular measurements, such as astronomy, navigation, and geodesy.
What are Revolutions (rev)?
A revolution (symbol: rev), also known as a turn or a full circle, is an angle equal to 360 degrees or 2π radians. It's a convenient unit for describing complete rotations in mechanics, engineering, and for measuring rotational speed (e.g., RPM).
Formulas
Radians = Degrees × (π/180)
To convert degrees to radians, multiply by π/180.
Degrees = Radians × (180/π)
To convert radians to degrees, multiply by 180/π.
Gradians = Degrees × (400/360)
To convert degrees to gradians, multiply by 400/360 or 10/9.
Degrees = Arcminutes / 60
To convert arcminutes to degrees, divide by 60.
Degrees = Arcseconds / 3600
To convert arcseconds to degrees, divide by 3600.
Revolutions = Degrees / 360
To convert degrees to revolutions, divide by 360.
Key Reference Points
- A right angle: 90° or π/2 radians or 100 gradians.
- A straight angle: 180° or π radians or 200 gradians.
- A full circle (one revolution): 360° or 2π radians or 400 gradians.
- An acute angle is less than 90°.
- An obtuse angle is greater than 90° but less than 180°.
- The angle of an equilateral triangle's corners is 60°.
- The hands of a clock at 3:00 form a 90° angle.
- The Earth's axial tilt is approximately 23.5°.
- The slope of a wheelchair ramp is typically no more than about 4.8°.
- The angle of a stop sign's corner is 135°.
Did You Know?
The division of a circle into 360 degrees originates from ancient Babylonians, who used a sexagesimal (base-60) system. The number 360 is highly divisible (by 2, 3, 4, 5, 6, 8, 9, 10, 12, etc.), making many fractional calculations easier. It's also close to the number of days in a year.
The sum of the interior angles in any Euclidean triangle is always 180 degrees (or π radians, or 200 gradians).
Using radians simplifies many calculus formulas involving trigonometric functions, such as the derivative of sin(x) being cos(x) only when x is in radians.
The Earth's axis is tilted at an angle of approximately 23.5 degrees relative to its orbital plane. This tilt is the primary cause of the seasons.
While degrees and radians measure two-dimensional (plane) angles, three-dimensional angles are measured in solid angles, with the SI unit being the steradian. A full sphere subtends a solid angle of 4π steradians.
In navigation, a 'bearing' or 'azimuth' is the horizontal angle between a reference direction (usually North) and the direction to an object. These are typically measured in degrees.
The Golden Angle, approximately 137.5 degrees, is related to the golden ratio. It appears frequently in nature, such as in the arrangement of florets in a sunflower head (phyllotaxis), as it provides optimal packing.
A sextant is an astronomical instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon, which is essential for celestial navigation.
When light passes from one medium to another, it bends or refracts. The relationship between the angles of incidence and refraction is described by Snell's Law, which is fundamental to the design of lenses and prisms.
In astronomy, the hour angle is a coordinate used in the equatorial coordinate system. It expresses the time since a celestial object last crossed the local celestial meridian, given as an angle.
The gradian (or gon) was invented as part of the metric system's effort to decimalize everything. Having a right angle as 100 gradians simplifies some surveying calculations, though it never achieved widespread use outside of specific fields.
Milliradians (mrads or 'mils') are used in long-range shooting to make corrections for bullet drop and wind. At 1000 meters, one mrad subtends exactly one meter, making it easy to calculate adjustments.
Parallax is the apparent shift in an object's position when viewed from two different lines of sight. By measuring this tiny angle (the parallax angle), astronomers can calculate the distance to nearby stars.
Just as a circle has 360 degrees, a full sphere has approximately 41,253 square degrees of solid angle. One steradian is about 3,283 square degrees.
In astrology and historical astronomy, the ecliptic (the Sun's apparent path) is divided into 12 'signs,' each occupying a 30-degree arc of the celestial sphere.
In physics, the angle of repose is the steepest angle of descent or dip relative to the horizontal plane to which a material can be piled without slumping. It's a key property for handling granular materials like sand or grain.
Brewster's angle is a specific angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface, with no reflection. It's the principle behind polarizing filters on cameras and sunglasses.
Architects use angles for everything from ensuring walls are perpendicular (90 degrees) to creating aesthetically pleasing roof pitches and designing complex geometric structures like geodesic domes.