Engineering & Physics CalcyZone Calculator
Parallel Resistor Calculator
Calculate the equivalent resistance of any number of resistors in parallel.
Equivalent resistance
59.9768 Ω
Resistors
3
Step-by-step working
- 1/R = 1/100 + 1/220 + 1/470 = 0.016673
- R = 59.9768 Ω
Mathematical Formula
1/R_eq = Σ 1/Rᵢ.
Overview & Explanation
Parallel resistors share voltage; their conductances add.
How It Works
- Sum reciprocals.
- Invert.
Practical Applications
- Circuit design.
- Getting non-standard values.
Example 1: 100, 220, 470 Ω
≈ 60.0 Ω.
1
Inputs
Resistances (Ω, comma separated): 100, 220, 470
= entered
2
Step 1
1/R = 1/100 + 1/220 + 1/470 = 0.016673
3
Step 2
R = 59.9768 Ω
4
Equivalent resistance
Result
= 59.9768 Ω
Example 2: two 1 kΩ
500 Ω.
1
Inputs
Resistances (Ω, comma separated): 1000, 1000
= entered
2
Step 1
1/R = 1/1000 + 1/1000 = 0.002
3
Step 2
R = 500 Ω
4
Equivalent resistance
Result
= 500 Ω
How it's calculated & sources
1/R_eq = Σ 1/Rᵢ.
Frequently Asked Questions
Is R_eq always smaller?
Yes, smaller than the smallest resistor.
Two resistors shortcut?
R = R₁R₂/(R₁ + R₂).
Zero ohms?
A short circuit makes R_eq = 0; enter positive values only.
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