Easily calculate the equivalent resistance of up to ten resistors in parallel with our Parallel Resistor Calculator.
Starting with Ohm's Law and Kirchhoff's Current Law:
\[R_{eq} = \frac{V}{I_{total}} = \frac{V}{\left(\frac{V}{R_1} + \frac{V}{R_2} + \frac{V}{R_3} + \cdots + \frac{V}{R_n}\right)}\]After voltage cancellation (V is equal across all branches):
\[R_{eq} = \frac{1}{\left(\frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \cdots + \frac{1}{R_n}\right)}\]The standard conductance form (G = 1/R):
\[\frac{1}{R_{eq}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \cdots + \frac{1}{R_n}\]Special case for two resistors (product over sum):
\[R_{eq} = \frac{R_1 \times R_2}{R_1 + R_2}\]