Resistor Replacement Calculator

Resistors

Calculates replacement values from standard E-series resistors after pressing the Calculate button. The result list contains exactly 12 suggestions: the 6 best combinations using two resistors and the 6 best combinations using three resistors.

Replace a resistor

Calculation starts only after pressing Calculate. Nominal values are used; real-world accuracy also depends on tolerance, temperature coefficient, load, and component availability.

View standard E-series resistor values

Best combinations

Type Combination Actual Error
Series connection

Rtotal = R1 + R2

Parallel connection

Rtotal = (R1 × R2) / (R1 + R2)

Mixed combination

Rtotal = R1 + (R2 ∥ R3) or (R1 + R2) ∥ R3