Calculadora de Transferidor
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
rad = graus × π/180; gradian = graus × 400/360
About this calculator
The Protractor Calculator is a practical tool for converting angles between degrees, radians, and gradians, as well as calculating supplementary and complementary angles. Simply enter an angle in degrees, and you instantly get the equivalents in other units, making it easier to work in fields like geometry, engineering, and physics.
It works by applying conversion formulas: for radians, multiply degrees by π and divide by 180; for gradians, multiply by 400 and divide by 360. Additionally, the complementary angle (90° minus the angle) and supplementary angle (180° minus the angle) are displayed, which are useful in trigonometry and technical drawing problems.
Use this calculator when you need to switch between angular measurement systems, such as in architecture projects, navigation, or graphics programming. For example, game programming often uses radians, but you might have measurements in degrees. It also helps verify if two angles are complementary or supplementary, speeding up schoolwork or professional calculations.
Be cautious when entering negative angles or values greater than 360°, as this may yield results outside the usual range. The calculator does not validate inputs, so ensure the angle is appropriate. Remember that π is approximated as 3.14159, so radian conversions may have slight differences compared to manual calculations with more decimals.
Frequently asked questions
What are gradians and when to use this unit?
Gradians divide a circle into 400 parts. They are mainly used in surveying and civil engineering in Europe, but in Brazil their use is rare.
Can I convert radians to degrees with this calculator?
No, the calculator expects degrees as input. To convert radians to degrees, you must first do the conversion manually (multiply by 180/π) and then use the tool.
What do complementary and supplementary angles mean?
Complementary angles sum to 90°, and supplementary angles sum to 180°. The calculator automatically shows these values based on the entered angle.
Does the calculator handle negative angles?
Yes, it accepts negative angles, but note that complementary and supplementary may result in values outside the usual range (0° to 90° or 0° to 180°).
How accurate are the conversions?
Conversions use π with 5 decimal places (3.14159), so radians have an accuracy of about 0.00001. Gradians are exact if the angle is an integer.