Resistors Color Code: How to Read and Use the Calculator
Quick Start: Using the Calculator
- Select the band count (3 / 4 / 5 / 6).
- Pick band colors in order starting from the first band.
- Read the result: resistance, tolerance, and temperature coefficient (for 6-band).
- If a color is uncertain, try the closest alternative and compare the result.
Reading direction: the tolerance or temperature coefficient band is usually at the far end; start from the opposite side.
Band Types Explained
3-band: digit, multiplier. No tolerance band implies ±20%.
4-band: digit, digit, multiplier, tolerance. Example: Brown–Black–Red–Gold → 1 kΩ ±5%.
5-band: digit, digit, digit, multiplier, tolerance (higher precision). Example: Brown–Black–Black–Red–Brown → 10 kΩ ±1%.
6-band: same as 5-band plus temperature coefficient (ppm/°C).
Worked Examples
- Red–Violet–Orange–Gold → 27 kΩ ±5% (4-band).
- Yellow–Violet–Black–Brown–Brown → 470 Ω ±1% (5-band).
- Brown–Black–Black–Gold–Brown–Brown → 10 Ω ±1%, 100 ppm/°C (6-band).
Common Mistakes
- Reading from the wrong end.
- Confusing gold/silver tolerance with significant digits.
- Mixing up red vs brown in dim light.
- Placing the temperature coefficient band incorrectly on 6-band parts.
FAQ
How do I tell the reading direction?
Start from the side opposite to the tolerance/tempco band.
What if there is no tolerance band?
Assume ±20%.
4-band vs 5-band?
5-band uses three digits for higher precision.
What does the temperature coefficient band mean?
It indicates how resistance changes with temperature (ppm/°C).
Glossary
- Digit: significant figure encoded by a color band.
- Multiplier: scales the value by a power of ten.
- Tolerance: allowable deviation from the nominal value.
- Temperature coefficient: change per degree Celsius (ppm/°C).