Resistor Calculator

Decode resistor colour band codes, calculate resistance values, and find series/parallel combinations.

Colour Band Decoder (4-band)

Band 1 (digit)

Band 2 (digit)

Band 3 (multiplier)

Band 4 (tolerance)

Series / Parallel

R1 (Ω)

R2 (Ω)

Decoded Value

Resistance

5,100 Ω

5.1 kΩ ±5%

Resistor Colour Code

The 4-band code: Band1 + Band2 = first two digits; Band3 = multiplier; Band4 = tolerance. Read from the band closest to one end.