Angle calculator

Enter an angle in degrees or radians and see what type of angle it is, its complementary and supplementary angle, how much is missing to a full turn (360°) and the same angle in the other unit.

Angle in

Fill in the fields; the answer appears here straight away.

How it works

  1. Enter the values

    Type the numbers or the formula. Decimals may use a point or a comma. No idea? Click Fill in an example.

  2. Instant answer

    The answer appears as you type, with the most important intermediate values.

  3. See the working

    Under "How it's worked out" you see the steps, handy for checking your own calculation.

Types of angle

  • acute: between 0° and 90°
  • right: exactly 90°
  • obtuse: between 90° and 180°
  • straight: exactly 180°
  • reflex: between 180° and 360°

Complementary and supplementary

Two angles are complementary when they add up to 90° (30° and 60°) and supplementary when they add up to 180° (110° and 70°). An angle larger than 90° has no complementary angle, and one larger than 180° no supplementary angle.

Angles larger than 360° or negative angles are also brought back to between 0° and 360°: 450° is the same direction as 90°.

Frequently asked questions

Is the angle calculator free?

Yes. The angle calculator is completely free, with no account, sign-up or usage limit.

How accurate is the result?

The tool calculates with your browser's number precision. For important calculations, always double-check what you entered.

Does it work on my phone?

Yes. The tool works in any modern browser on a phone, tablet or computer.