Phasor to Rectangular Form Calculator


Phasor to Rectangular Form Calculator

Convert phasor/polar coordinates (magnitude and angle) to rectangular coordinates (real and imaginary).



The length or amplitude of the phasor (e.g., Volts, Amps).


The phase angle of the phasor.


Select whether the angle is in degrees or radians.


Intermediate Values

Formula: x = r * cos(θ), y = r * sin(θ)


Phasor Visualization

Dynamic chart showing the phasor on the complex plane.

Example Conversions

Conversion of a phasor with magnitude 10 at various common angles.
Phasor Form (r∠θ) Rectangular Form (x + jy)
10 ∠ 0° 10.00 + j0.00
10 ∠ 30° 8.66 + j5.00
10 ∠ 45° 7.07 + j7.07
10 ∠ 60° 5.00 + j8.66
10 ∠ 90° 0.00 + j10.00
10 ∠ 180° -10.00 + j0.00

What is a Phasor to Rectangular Form Conversion?

A phasor is a complex number used in physics and engineering to represent a sinusoidal function. It has a magnitude (or amplitude) and a phase angle. This representation is known as the **polar form** (r∠θ). However, for many calculations, especially addition and subtraction of waves, it’s easier to work with them in **rectangular form** (x + jy). The process of finding these x and y components is what this calculator does. Knowing how to convert phasor to rectangular form using calculator tools like this one simplifies complex circuit analysis significantly.

This conversion is fundamental in AC (Alternating Current) circuit analysis. Instead of dealing with complicated trigonometric functions of time, engineers use phasors to turn differential equations into simpler algebraic ones. The rectangular form splits the single phasor into two orthogonal components: the ‘real’ part (x) on the horizontal axis and the ‘imaginary’ part (y) on the vertical axis.

The Phasor to Rectangular Formula and Explanation

The conversion from polar (phasor) form to rectangular form uses basic trigonometry. Given a phasor with magnitude `r` and angle `θ`, the real component `x` and imaginary component `y` are found using the following formulas:

  • Real Part (x): `x = r * cos(θ)`
  • Imaginary Part (y): `y = r * sin(θ)`

The final rectangular form is then expressed as `x + jy`. In electronics, `j` is used to denote the imaginary unit (the square root of -1) to avoid confusion with `i`, which often represents current. Our guide on complex number forms provides more detail.

Variables in Phasor Conversion
Variable Meaning Unit (Auto-Inferred) Typical Range
r Magnitude / Amplitude Volts, Amps, Ohms, or Unitless Any non-negative number (0 to ∞)
θ Phase Angle Degrees or Radians 0 to 360° or 0 to 2π rad
x Real Component Same as magnitude -r to +r
y Imaginary Component Same as magnitude -r to +r

Practical Examples

Understanding how to convert phasor to rectangular form using calculator functionality is best illustrated with examples.

Example 1: Converting a Voltage Phasor

  • Inputs:
    • Magnitude (r): 120 V
    • Angle (θ): 45°
    • Units: Volts (V) and Degrees
  • Calculation:
    • Real Part (x) = 120 * cos(45°) = 120 * 0.7071 = 84.85 V
    • Imaginary Part (y) = 120 * sin(45°) = 120 * 0.7071 = 84.85 V
  • Result: The rectangular form is 84.85 + j84.85 V.

Example 2: Converting an Impedance Phasor

  • Inputs:
    • Magnitude (r): 50 Ω
    • Angle (θ): -60° (a capacitive load)
    • Units: Ohms (Ω) and Degrees
  • Calculation:
    • Real Part (x) = 50 * cos(-60°) = 50 * 0.5 = 25 Ω
    • Imaginary Part (y) = 50 * sin(-60°) = 50 * -0.866 = -43.30 Ω
  • Result: The rectangular form is 25 – j43.30 Ω.

How to Use This Phasor to Rectangular Form Calculator

This tool is designed for speed and accuracy. Follow these simple steps:

  1. Enter Magnitude (r): Input the total magnitude (length) of your phasor in the first field.
  2. Enter Angle (θ): Input the angle of the phasor in the second field.
  3. Select Angle Unit: Use the dropdown to choose whether your angle is in Degrees or Radians. This is a critical step for a correct conversion.
  4. Review Results: The calculator instantly provides the rectangular form (x + jy), along with the individual real (x) and imaginary (y) components. The results are updated in real-time as you type.
  5. Visualize: The dynamic chart plots the phasor on the complex plane, giving you a graphical representation of the conversion.

For reverse calculations, you might be interested in a Rectangular to Polar Converter.

Key Factors That Affect Phasor Conversion

  • Angle Unit: The most common error is using the wrong unit. `cos(30)` is very different in degrees vs. radians. Always double-check your selection.
  • Sign of the Angle: A positive angle typically implies an inductive characteristic in circuits, while a negative angle implies a capacitive one. This directly affects the sign of the imaginary component (y).
  • Quadrant: The angle determines the quadrant the phasor lies in, which in turn determines the signs of both the real (x) and imaginary (y) parts. For example, an angle between 90° and 180° will have a negative x and a positive y.
  • Magnitude: This value scales both the real and imaginary parts proportionally. Doubling the magnitude will double both x and y.
  • Calculator Precision: The number of decimal places used in the cosine and sine calculations will affect the precision of the final result. Our calculator uses high precision for accurate conversions.
  • Application Context: Whether the phasor represents voltage, current, or impedance doesn’t change the math, but it’s crucial for interpreting the results correctly. A great resource is our Ohm’s Law Calculator.

Frequently Asked Questions (FAQ)

1. What is the difference between polar and rectangular form?

Polar form describes a point or vector using a magnitude (distance from origin) and an angle, like `10∠30°`. Rectangular form describes the same point using its horizontal (x) and vertical (y) coordinates, like `8.66 + j5.00`.

2. Why is ‘j’ used instead of ‘i’ for the imaginary unit?

In electrical engineering, ‘i’ is commonly used to represent instantaneous current, so ‘j’ is used for the imaginary unit (√-1) to prevent confusion.

3. When should I use rectangular form?

Rectangular form is ideal for adding or subtracting complex numbers or phasors. You simply add or subtract the real parts and the imaginary parts separately.

4. Can I convert a negative magnitude?

By convention, the magnitude ‘r’ of a phasor is always a non-negative number. A negative sign is typically handled by adjusting the angle by 180°.

5. How do I handle an angle greater than 360 degrees?

You can subtract multiples of 360° (or 2π radians) until the angle is within the 0-360° range. For example, 370° is equivalent to 10°.

6. What does a zero imaginary part mean?

If the imaginary part (y) is zero, the phasor lies entirely on the horizontal (real) axis. This represents a purely resistive component in an AC circuit, with a phase angle of 0° or 180°.

7. What does a zero real part mean?

If the real part (x) is zero, the phasor lies entirely on the vertical (imaginary) axis. This represents a purely reactive (inductive or capacitive) component, with a phase angle of 90° or -90°.

8. Is this the same as Cartesian coordinates?

Yes, the rectangular form (x, y) corresponds directly to the Cartesian coordinate system, where the x-axis is the real axis and the y-axis is the imaginary axis.

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