(a+bi)(c+di)Combine real parts and imaginary parts separately; i² = −1.
Algebra & functions
Complex number
Add, subtract, multiply and inspect complex numbers.
LocalFree
Study & learning use only
Use the result as a learning aid and verify important calculations against your course material or instructor.
Use the result as a learning aid and verify important calculations against your course material or instructor.
This tool runs on your device in the browser.
Instructions and limitations
TOOL GUIDE
What this tool is for
Complex number — Add, subtract, multiply and inspect complex numbers.
Useful for practice, understanding the method, and checking homework steps where outside tools are allowed.
Common uses
- Practice a formula or method
- Check your working
- Review before a lesson or exam
Study and learning use only
Use the result for practice and understanding, not as a guaranteed answer. Verify important calculations and follow your school, university, and academic-integrity rules.
EXPLANATION & EXAMPLE
Understand the result—not just the number
Use the starting values, then change one input to see its effect.After calculating, the tool shows the values used and the working so you can check it.