Interactive 5-Band Resistor Calculator
Choose resistor band colors to decode resistance value, multiplier, and tolerance.
What is a 5-band resistor calculator?
A 5-band resistor calculator converts resistor color bands into an electrical resistance value. In a 5-band resistor, the first three bands represent significant digits, the fourth band is the multiplier, and the fifth band is the tolerance. This format is common for precision resistors and engineering work where tighter tolerances matter.
Instead of memorizing every color code combination, you can use this calculator to instantly decode values in ohms, kilo-ohms, mega-ohms, and giga-ohms. It is especially useful for electronics troubleshooting, PCB assembly, and educational lab work.
How the 5-band resistor color code works
Band meaning
- Band 1: First significant digit
- Band 2: Second significant digit
- Band 3: Third significant digit
- Band 4: Multiplier (power of ten, including gold/silver for decimal multipliers)
- Band 5: Tolerance (allowed percentage variation from nominal value)
Formula
Resistance = (100×Band1 + 10×Band2 + Band3) × Multiplier
Range = Resistance ± (Tolerance% × Resistance)
Digit colors (bands 1-3)
- Black = 0
- Brown = 1
- Red = 2
- Orange = 3
- Yellow = 4
- Green = 5
- Blue = 6
- Violet = 7
- Gray = 8
- White = 9
Multiplier and tolerance quick guide
Common multipliers
- Silver ×0.01
- Gold ×0.1
- Black ×1
- Brown ×10
- Red ×100
- Orange ×1,000
- Yellow ×10,000
- Green ×100,000
- Blue ×1,000,000
Common tolerance bands
- Brown ±1%
- Red ±2%
- Green ±0.5%
- Blue ±0.25%
- Violet ±0.1%
- Gray ±0.05%
- Gold ±5%
- Silver ±10%
Example: decode a resistor manually
Suppose the colors are Brown, Black, Black, Red, Brown:
- Digits: 1, 0, 0 → 100
- Multiplier: Red → ×100
- Nominal value: 100 × 100 = 10,000 Ω (10 kΩ)
- Tolerance: Brown → ±1%
- Range: 9.9 kΩ to 10.1 kΩ
Tips for accurate resistor reading
- Read from the end where bands are closer together; tolerance band is often spaced slightly apart.
- Use good lighting to distinguish red/orange and blue/violet.
- If the resistor is old or faded, verify with a digital multimeter.
- When precision matters, always account for tolerance and temperature effects.
- Cross-check with a resistor color code chart if you are unsure.
Why 5-band resistors are popular in precision electronics
A 4-band resistor gives two significant digits, while a 5-band resistor gives three. That extra digit improves precision and makes the nominal value more specific. In analog circuits, sensor conditioning, instrumentation, and calibration networks, this added precision can reduce error and improve repeatability.
If you are learning electronics, this tool doubles as a practical resistor color code trainer and an ohm-value calculator. Use it to practice identifying band combinations quickly before soldering components into your circuit.