Circuit Resistance
R1 (Ω)
R2 (Ω)
R3 (Ω, optional)
Resistors in series simply add together. Resistors in parallel have a combined resistance lower than any individual resistor — current has multiple paths, reducing overall opposition.
💡
Tip: Adding resistors in parallel decreases total resistance; adding in series increases it. Opposite to what you might expect with batteries.
⭐
Fun Fact
Your home's electrical outlets are all in parallel — so adding devices doesn't increase total voltage, only current draw.
References
🔒
100% Free
No sign-up ever
✓
Accurate
Verified formulas
⚡
Instant
Results as you type
📱
Mobile Ready
All devices