Resistor Color Code Calculator
Select the color bands on your resistor to decode its resistance value, tolerance, and temperature coefficient.
Frequently Asked Questions
How do I read a resistor color code?
Hold the resistor with the grouped bands on the left side. The tolerance band (often gold or silver) is usually slightly separated and should be on the right. Read the bands from left to right:
- 4-band: 1st digit, 2nd digit, multiplier, tolerance
- 5-band: 1st digit, 2nd digit, 3rd digit, multiplier, tolerance
- 6-band: 1st digit, 2nd digit, 3rd digit, multiplier, tolerance, temperature coefficient
For example, a 4-band resistor with Red-Violet-Orange-Gold bands reads: 2-7 × 1,000 = 27,000 Ω (27 kΩ) ±5%.
What is the mnemonic for resistor color codes?
Several mnemonics exist to remember the color-to-digit mapping. A common one is:
“Black Bears Robbed Our Yellow Garlic, Bringing Very Good Wheat”
Each word's first letter matches a color: Black=0, Brown=1, Red=2, Orange=3, Yellow=4, Green=5, Blue=6, Violet=7, Grey=8, White=9.
What is the difference between 4-band, 5-band, and 6-band resistors?
4-band resistors are the most common and have 2 significant digits, a multiplier, and a tolerance band. They are used for standard-value resistors (e.g., 10 kΩ ±5%).
5-band resistors add a third significant digit, providing greater precision (e.g., 10.0 kΩ ±1%). These are typical for precision or metal-film resistors.
6-band resistors include all five bands plus a temperature coefficient band that indicates how much resistance changes with temperature, expressed in ppm/°C.
Why do resistors use color codes instead of printed values?
Color bands can be read from any orientation and remain visible even when the component is mounted on a circuit board. Printed numbers would be too small to read on tiny through-hole resistors and could wear off or be obscured by solder. The color code system was standardized internationally by the IEC 60062 standard.
Resistor Color Code Chart
Complete reference table showing digit values, multipliers, tolerances, and temperature coefficients for each color band:
| Color | Digit | Multiplier | Tolerance | Temp. Coeff. |
|---|---|---|---|---|
| Black | 0 | ×1 | — | — |
| Brown | 1 | ×10 | ±1% | 100 ppm/°C |
| Red | 2 | ×100 | ±2% | 50 ppm/°C |
| Orange | 3 | ×1K | — | 15 ppm/°C |
| Yellow | 4 | ×10K | — | 25 ppm/°C |
| Green | 5 | ×100K | ±0.5% | — |
| Blue | 6 | ×1M | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10M | ±0.1% | 5 ppm/°C |
| Grey | 8 | — | ±0.05% | — |
| White | 9 | — | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
| None | — | — | ±20% | — |
How to Identify Resistor Band Orientation
Knowing which end to read from is essential for getting the correct value:
- Spacing: The tolerance band (last band) is usually spaced slightly further from the other bands.
- Color: The first band is never gold or silver — if one end has gold or silver, that is the tolerance band (read from the opposite end).
- Band count: On 5-band and 6-band resistors, the grouped bands (3 significant digits) are closer together on one side.
Common Resistor Values (E12 Series)
The E12 series contains 12 standard values per decade, widely used in general electronics:
10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82
These values repeat at each decade: 100, 120, 150, … 1K, 1.2K, 1.5K, … 10K, 12K, 15K, and so on. The E24 and E96 series offer finer granularity for precision applications.
Related Calculators
- Ohm's Law Calculator (V/A/W/Ω) — calculate V, I, R, and P from any two values
- Parallel Resistor Calculator — calculate total resistance for parallel resistors
- Voltage Drop Calculator — calculate wire voltage drop per NEC standards
- Wire Size Calculator — find the right AWG wire gauge for your circuit
- Watts / Amps / Volts Calculator — convert power to current for DC and AC circuits
Resistor color codes follow the IEC 60062 standard. Color band values and tolerances are internationally standardized.
