Resistors in Series/Parallel Calculator
Calculate total resistance for up to 5 resistors connected in series or parallel.
Essential for circuit design.
Total Resistance
Series Resistors: Resistances add up directly.
R_total = R₁ + R₂ + R₃ + ...
Parallel Resistors: Reciprocals add up.
1/R_total = 1/R₁ + 1/R₂ + 1/R₃ + ...
Key rules:
- Series: Total is always more than the largest single resistor
- Parallel: Total is always less than the smallest single resistor
- Two equal resistors in parallel = half of one resistor
Quick parallel formula (2 resistors):
R_total = (R₁ × R₂) / (R₁ + R₂)
Enter up to 5 resistor values. Leave unused fields blank.