Convert Polar to Cartesian Coordinates

Point labeled in both polar and cartesian coordinates.

To convert a point from the polar coordinate system to the Cartesian coordinate system, the trigonometric functions sine and cosine are used to solve for the and coordinate of the point. A point in the polar coordinate system is in the form of and a point in the cartesian coordinate system is in the form of . The formulas for the conversion are shown below:

Note, that by convention, radians are used to measure angles in polar coordinates. A full rotation in radians is equal to (tau) radians and a full rotation in degrees is equal to . The substitution can be used to translate between the two systems.

Example 1

Example point in polar and cartesian coordinate

This example shows how to convert the point in the polar coordinate system to its cartesian coordinate equivalent.

  1. Start by setting up the formula for conversion.

  2. Substitute the radius and angle of the polar coordinates into the formula.

  3. Calculate the result of the multiplication.

    Then since we can write the coordinates of the point as:

    The cartesian coordinates of the point in polar coordinates are .

Example 2

Example point in polar and cartesian coordinate

This example shows how to convert the point in the polar coordinate system to its cartesian coordinate equivalent.

  1. Start by setting up the formula for conversion.

  2. Substitute the radius and angle of the polar coordinates into the formula.

  3. Calculate the result of the multiplication.

    Then since we can write the coordinates of the point as:

    The cartesian coordinates of the polar point are .

Explanation

The formula used on this page can be derived using the circle definitions of the trigonometric functions sine and cosine and then solving for the anc component of the point.

Unit Circle Labeled