Enter your Number of Resistors and each resistor's value (R₁ through R₄) with their respective units, and this Resistors in Parallel Calculator finds the Equivalent Resistance of your parallel circuit — plus the Total Current and Total Power drawn at a reference voltage of 5V.
Equivalent Resistance
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Total Current (at 5V)
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Total Power (at 5V)
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For two resistors in parallel, use the formula: 1/R_total = 1/R1 + 1/R2, or the simplified formula: R_total = (R1 × R2) / (R1 + R2). The equivalent resistance is always less than the smallest individual resistor.
In parallel circuits, adding more resistors creates additional current paths. More paths for current to flow means less total resistance, which is why the equivalent resistance decreases as you add more resistors in parallel.
Yes, in a parallel circuit, the voltage across each resistor is the same and equals the source voltage. This is a key characteristic that distinguishes parallel circuits from series circuits.
For multiple resistors in parallel, the formula is: 1/R_total = 1/R1 + 1/R2 + 1/R3 + ... + 1/Rn. This means you add the reciprocals of all individual resistances and then take the reciprocal of the sum.
If you know the total equivalent resistance and all other resistor values, rearrange the parallel formula to solve for the unknown resistor: 1/R_unknown = 1/R_total - 1/R1 - 1/R2 - ... (for all known resistors).
Yes, this calculator automatically handles unit conversion. You can enter resistors in ohms (Ω), kiloohms (kΩ), or megaohms (MΩ), and the calculator will convert everything to the appropriate units for calculation.
When one resistor is much smaller than the others in a parallel circuit, it dominates the equivalent resistance. The total resistance will be close to the value of the smallest resistor, as current prefers the path of least resistance.