parallel resistor calculator

enter any two values below and press the calculate button.

parallel resistor calculator online calculator can calculate the resistance value of 2 to 4 resistors in parallel. the units in the parallel resistance calculation formula should be consistent.

the calculation formula of the parallel resistor resistance is: 1/r and =1/r1+1/r2+1/r3+...1/rn

for example: the resistance r of four resistors 10ω, 10ω, 100ω, and 100ω connected in parallel is:

1/R=1/10+1/10+1/100+1/100

1/r and=22/100

r and≈4.5ω;

another example: the resistance values of two 820ω resistors are r and 1.5kω; the parallel connection is:

1/r and=1/820+1/1500

1/r sum=116/61500

r and≈530.2ω;

two typical applications of parallel resistors:

1. no suitable resistor: when you cannot find a resistor with suitable resistance value, you can get it by connecting multiple resistors in parallel.

2. the resistor power does not meet the requirements: for example, 1w 25ω; a resistor is needed in the circuit but is not available at hand, four 1/2w 100ω resistors. resistors can be used in parallel instead. taking into account the uniform power distribution, four 1/2w resistors with a resistance of 100ω are used. it can be used instead. the resistor values should be as consistent as possible.

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