Parallel Resistance Calculator
Calculate the total resistance of resistors connected in parallel. Enter up to 10 resistor values in ohms.
Published by:
isCalculator Editorial Team
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How to use this tool?
This calculator computes the total resistance of resistors connected in parallel.
- Enter resistor values in ohms (Ω) into the fields labeled R1 through R10. Use decimal numbers if needed (e.g., 100, 220, 4.7).
- At least two resistors are required. Leave unused fields blank.
- Click Calculate (or press Enter in any input field) to see the result.
- The result shows the equivalent parallel resistance in ohms, rounded to two decimal places.
- Below the result, a step-by-step formula shows how the value was derived using the reciprocal sum method:
1/Rt = 1/R1 + 1/R2 + ... - Click Clear to reset all fields and start a new calculation.
Note: Values must be non-negative and greater than zero. If you enter an invalid number or zero, an error message will appear.
Previous Results
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Frequently Asked Questions
The total resistance Rt of resistors in parallel is given by 1/Rt = 1/R1 + 1/R2 + ... + 1/Rn. For two resistors, a simpler formula is Rt = (R1 * R2) / (R1 + R2).
You can enter up to 10 resistor values. At least two are required for a valid calculation.
Yes, you can enter decimal values (e.g., 100.5). The calculator will round the result to two decimal places.
The result is in ohms (Ω). Make sure all input values are in ohms as well.