Home / Complex Number Calculator

Complex Number Calculator

Complex numbers combine a real component and an imaginary component, written a + bi where i² = −1. This calculator returns sums, differences, products, quotients and magnitudes for two complex values.

How to use this calculator

  1. Enter real and imaginary components separately for A and B. A negative imaginary component represents a term such as −4i.
  2. Check the labels and units before applying the result to a real task.
  3. Change one input at a time when comparing scenarios.

Formula and method

(a+bi)(c+di)=(ac−bd)+(ad+bc)i; |a+bi|=√(a²+b²)

  • (a+bi)(c+di)=(ac−bd)+(ad+bc)i; |a+bi|=√(a²+b²)
  • A quotient by zero is undefined. Displayed values are rounded, so use sufficient precision when chaining several operations.

Worked examples

Worked example

Take A = 3 + 2i and B = 1 − 4i.

A+B = 4−2i; A×B = 11−10i; |A| = √13 ≈ 3.606.

A+B = 4−2i; A×B = 11−10i; |A| = √13 ≈ 3.606.

Understanding the result

Complex numbers combine a real component and an imaginary component, written a + bi where i² = −1. This calculator returns sums, differences, products, quotients and magnitudes for two complex values.

A quotient by zero is undefined. Displayed values are rounded, so use sufficient precision when chaining several operations.

Important notes

A quotient by zero is undefined. Displayed values are rounded, so use sufficient precision when chaining several operations.

Displayed values are rounded for readability; retain appropriate precision when continuing a calculation.

Frequently asked questions

What does the imaginary unit i represent?

By definition, i² = −1. A complex number has a real part and an imaginary coefficient, which allows arithmetic beyond the real number line.

Why is division by zero undefined?

No complex number multiplied by zero can produce a non-zero numerator, so a quotient with a zero denominator does not exist.

Is magnitude the same as the real part?

No. Magnitude is the non-negative distance from the origin, √(real² + imaginary²), while the real part is just one component.

Affiliate recommendations

Tools related to Complex Number Calculator

These tools are selected for the calculator topic. The Calc Studio may earn a commission from purchases made through affiliate links.

  • Growth Wise SAT & ACT prep Visit partner ↗

    SAT and ACT study tools, flashcards, and preparation resources for students.

See the Affiliate Disclosure for details.

Related calculators

  • Arithmetic Sequence Calculator — Find the nth term and finite sum of an arithmetic sequence with a constant difference.
  • Mixed Number Calculator — Convert between mixed numbers, improper fractions, and decimal values.
  • Vector Magnitude Calculator — Calculate the magnitude of a two- or three-dimensional vector from its components.
  • 2×2 Matrix Calculator — Add, subtract and multiply 2×2 matrices and calculate each determinant with transparent row and column inputs.
  • Average Calculator — Calculate the mean, median, mode, and range of any set of numbers.
  • Circle Calculator — Calculate circle area, circumference, and diameter from radius.

Related explanations

Learn the method behind the number or compare the terminology before using the calculator.

  • How to Calculate a Z-Score — Learn how a z-score shows how far a value is from the mean in standard-deviation units.
  • How to Calculate Salary from an Hourly Rate — Convert hourly pay into weekly, monthly, and annual estimates and understand the assumptions behind the result.
  • Percent Difference — Understand percent difference, when it is appropriate, and how it differs from percentage change and percent error.

This page provides a calculation tool plus explanatory information so you can understand what the result means and when the underlying method may not fit your situation.

Explore more calculation resources

Keep exploring related tools, explanations, conversions, and topic pages in The Calc Studio. These links are selected around the subject of this page so you can move to the next useful calculation without returning to search.

Related calculators

  • Mixed Number Calculator — Convert between mixed numbers, improper fractions, and decimal values.
  • Average Calculator — Calculate the mean, median, mode, and range of any set of numbers.
  • Vector Magnitude Calculator — Calculate the magnitude of a two- or three-dimensional vector from its components.
  • 2×2 Matrix Calculator — Add, subtract and multiply 2×2 matrices and calculate each determinant with transparent row and column inputs.
  • Arithmetic Sequence Calculator — Find the nth term and finite sum of an arithmetic sequence with a constant difference.
  • Modulo Calculator — Find the normalized remainder from division for cycle, modular arithmetic, and number theory problems.
Browse by categoryMath CalculatorsBusiness CalculatorsDate & Time CalculatorsEveryday ToolsScience & Electronics CalculatorsFinancial Calculators

Task collections

  • Calculators for Students — Free student calculators for grades, percentages, fractions, probability, normal distributions, matrices, vectors, complex numbers, statistics, geometry, and scientific math.
  • Math & Statistics Calculators — Free math and statistics calculators for Bayes theorem, set operations, matrices, complex numbers, vector products, normal distributions, averages, percentages, standard deviation, geometry, equations, and number systems.
  • Time & Date Calculators — Free time and date calculators for age, date differences, date arithmetic, business days, time duration, time zones, and countdowns.
  • Science & Electronics Calculators — Free science and electronics calculators for projectile motion, force, buoyancy, fluid pressure, Reynolds number, heat transfer, capacitors, RC time constants, resistance, and electrical relationships.

Related guides

  • How to Calculate a Z-Score — Learn how a z-score shows how far a value is from the mean in standard-deviation units.
  • How to Calculate Age from a Date of Birth — Learn how exact age is calculated using years, months, and days rather than a rough year difference.
  • How to Calculate Salary from an Hourly Rate — Convert hourly pay into weekly, monthly, and annual estimates and understand the assumptions behind the result.

Related terms

  • Markup — Learn what markup means, how markup is calculated from cost and selling price, and how it differs from margin.
  • Percent Difference — Understand percent difference, when it is appropriate, and how it differs from percentage change and percent error.
  • Budget — Learn what a budget is and how simple income-minus-expenses calculations can support planning.

Useful conversions

  • °C to °F — Convert Celsius to Fahrenheit with a free temperature converter, formula, examples, and common temperatures.
  • °F to °C — Convert Fahrenheit to Celsius with a free temperature converter, formula, examples, and common temperatures.
  • cm to feet — Convert centimeters to feet with a free cm to feet converter, formula, examples, and a quick reference table.

Browse all calculators · Read all guides · Open the glossary · See all converters · Browse collections

Want to keep learning? Move from a calculator to its formula guide, glossary definition, unit conversion, or task collection to compare related methods and tools.

Optional Premium: save calculation history across visits and remove promotional blocks. See Premium.