How do you calculate resistors in parallel?
Add the reciprocal of each resistance, then take the reciprocal of the total: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 and so on.
Calculate total resistance for two or more resistors in parallel. Enter resistor values in ohms and see the reciprocal formula and example.
Total Resistance
54.55Ω
1/R_total = 1/R1 + 1/R2 + ...
Enter two or more positive resistor values separated by commas. The calculator adds their reciprocals and takes the reciprocal of that sum to find total parallel resistance.
1/R_total = 1/R1 + 1/R2 + ...
For 100 ohms, 200 ohms, and 300 ohms in parallel, 1/R = 1/100 + 1/200 + 1/300. The total resistance is about 54.55 ohms.
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Add the reciprocal of each resistance, then take the reciprocal of the total: 1/Rtotal = 1/R1 + 1/R2 + 1/R3 and so on.
For two resistors, the shortcut is Rtotal = (R1 x R2) / (R1 + R2).
Yes. For positive resistor values, total parallel resistance is lower than the smallest individual resistor.