Angle Converter
- 1 / (pi / 180) 57.29577951 degree
This page converts an angle from one unit into another. Every value passes through the radian, the SI unit angle is held in, and angle stays angle: a unit only converts inside its own dimension.
How do you convert an angle between degrees, radians and gradians?
Pick the unit you have, pick the unit you want, and type the value. The page multiplies by the factor between the two and prints the arithmetic under the result, so the answer and the working are the same object.
90 degrees is pi/2 radians, about 1.5707963268 rad. Multiply degrees by pi/180 for radians and radians by 180/pi for degrees; a gradian is 0.9 degrees.
- Choose the unit your value is in. This page opens on the radian.
- Choose the unit you want it in. This page opens on the degree.
- Type the value. The result and the factor behind it appear together.
- Read the working. It converts into the radian first and out again, which is the same two lines you would write by hand.
Angle Conversion Table
One row per unit this page offers, each measured against the radian. The last column says whether the factor is a definition or a reading of one.
| Unit | Symbol | In the SI unit | Exact? |
|---|---|---|---|
| radian | rad | 1 | exact |
| milliradian | mrad | 0.001 | exact |
| degree | deg | pi / 180 (0.017453292519943295) | rounded |
| gradian | gon | pi / 200 (0.015707963267948967) | rounded |
| turn | turn | 2 pi (6.283185307179586) | rounded |
| minute of arc | arcmin | pi / 10800 (0.0002908882086657216) | rounded |
| second of arc | arcsec | pi / 648000 (0.00000484813681109536) | rounded |
Worked Examples
The questions the bank ranked highest for this page, answered with the working.
What is 1 radian in degrees?
- 1 / (pi / 180) 57.29577951 degree
1 rad = 57.29577951 deg Exactly 180 / pi.
What is 45 degrees in radians?
- 45 x (pi / 180) 0.7853981634 radian
45 deg = 0.7853981634 rad Exactly pi / 4.
Where These Factors Come From
Every number above is read from the knowledge base rather than computed for the page. These are the statements it holds for angle.
- A full turn is 2 pi radians, 360 degrees or 400 gradians. One degree is exactly pi/180 radians, so one radian is 180/pi degrees, about 57.29577951308232 degrees.
- One degree is 60 minutes of arc and 3600 seconds of arc, so decimal degrees = degrees + minutes/60 + seconds/3600.
- An exact factor is a definition rather than a measurement. 1 in = 25.4 mm and 1 lb = 0.45359237 kg were fixed by the 1959 international yard and pound agreement, so they never gain another digit.
- How this page reports a result result in the target angle unit; radians are given as a multiple of pi and as a decimal
SI prefixes on this page
| Prefix | Symbol | Factor |
|---|---|---|
| milli | m | 10^-3 |
Degrees, Radians or Gradians?
The radian is the SI unit, and it is what every trigonometric function expects. Degrees and gradians divide the same turn into different numbers of parts, so an angle carries no meaning until the unit is named beside it.
The rule behind this factor is the same for every unit - why a conversion factor is a ratio equal to one.
Frequently Asked Questions
How do you convert degrees to radians?
Multiply the degree value by pi/180. To go back, multiply the radian value by 180/pi.
How do you convert an angle to degrees, minutes and seconds?
Decimal degrees = degrees + minutes/60 + seconds/3600, because one degree is 60 minutes of arc and 3600 seconds of arc.
How many degrees is a gradian?
Exactly 0.9 degrees, because a full turn is 400 gradians.
How many radians are in a full turn?
2 pi rad, about 6.2831853072 rad.
Related Conversions
The rest of the family sits on every measurement family in one place.