Decode 4/5-band THT resistors and SMT markings; encode any value to colour bands
Each colour band encodes a digit or multiplier. A 4-band resistor uses two significant digits + multiplier + tolerance. A 5-band resistor adds a third significant digit for precision parts (±1% or tighter).
Band 1: first digit · Band 2: second digit · Band 3: multiplier (×10ⁿ) · Band 4: tolerance (Gold = ±5%, Silver = ±10%)
3-digit code: first two digits are significant figures, third is power-of-ten in Ω. Code 103 = 10 × 10³ = 10 kΩ. EIA-96 codes index a 96-value lookup table.
Resistors are made only in E12 (12/decade, ±10%) and E24 (24/decade, ±5%) preferred values. The calculator shows the nearest available off-the-shelf part.