Use our Resistor Color Code Calculator to decode resistor values based on color bands. Select the colors for the bands, multiplier, and tolerance to get the resistance value quickly and accurately.
Resistor Color Code Calculator: Read Any Resistor in Seconds
A resistor color code is a standardized system that uses colored bands to show a resistor’s value in ohms (Ω), along with its tolerance (and sometimes temperature coefficient and reliability). Because most small resistors don’t have room for printed numbers, the color bands act as a quick “label” you can read at a glance. This calculator focuses specifically on resistor color codes (not capacitor or inductor markings).
Why resistors use color bands
Resistors are one of the most common components in electronics, used to limit current, divide voltage, set gain, and protect circuits. The color bands make it easy to identify the correct part when troubleshooting, building a circuit, or checking a mixed assortment of components.
How the resistor color code works
The resistor band system is an international standard (commonly referenced as IEC 60062). Each color corresponds to a number, and the position of the band determines what that number means.
Most resistors are read from left to right. A common clue is that the tolerance band (often gold or silver) is separated by a slightly larger gap and sits at the far right.
4-band resistors (most common)
- 1st band = first significant digit
- 2nd band = second significant digit
- 3rd band = multiplier (power of ten)
- 4th band = tolerance (±%)
Example: Green – Red – Blue – Gold
- Green = 5, Red = 2 → significant digits = 52
- Blue multiplier = × 1,000,000
- 52 × 1,000,000 = 52,000,000 Ω (52 MΩ)
- Gold tolerance = ±5% → range is 49.4 MΩ to 54.6 MΩ
5-band and 6-band resistors
5-band resistors (higher precision)
A 5-band resistor adds an extra significant digit for more accurate values:
- 1st band = 1st digit
- 2nd band = 2nd digit
- 3rd band = 3rd digit
- 4th band = multiplier
- 5th band = tolerance
These are common in precision applications where tighter tolerance matters.
6-band resistors (precision + temperature coefficient)
A 6-band resistor is like a 5-band, but includes a temperature coefficient (tempco) band:
1–3. Significant digits
4. Multiplier
5. Tolerance
6. Temperature coefficient (ppm/°C or ppm/K)
Tempco tells you how much the resistance changes as temperature changes—important for measurement circuits, sensors, and precision analog designs.
Color values, multipliers, and tolerance
Significant digit colors (0–9)
- Black 0, Brown 1, Red 2, Orange 3, Yellow 4
- Green 5, Blue 6, Violet 7, Grey 8, White 9
Multiplier colors (×10ⁿ)
- Black ×1, Brown ×10, Red ×100, Orange ×1k, Yellow ×10k
- Green ×100k, Blue ×1M, Violet ×10M, Grey ×100M, White ×1B
Tolerance band (±%)
- Brown ±1%, Red ±2%, Green ±0.5%, Blue ±0.25%
- Violet ±0.1%, Grey ±0.05%, Gold ±5%, Silver ±10%
Helpful tips for reading resistor bands
- Start from the side with bands closer together (the tolerance band is usually spaced apart on the right).
- If you get an odd value, double-check orientation—reading the resistor backwards is the most common mistake.
- Use a calculator (like this one) to instantly convert bands to Ω, kΩ, or MΩ, plus tolerance range.
Resistor color code exceptions (common edge cases)
5-band resistors with gold or silver in the 4th band
- First two bands are significant digits
- 3rd band is multiplier
- 4th band is tolerance
- 5th band is temperature coefficient
Alternate colors on high-voltage resistors
On certain high-voltage resistor types, gold and silver may be replaced by other colors (such as yellow or grey) depending on manufacturer and coating requirements.
Single black band = zero-ohm resistor
A resistor with a single black band is typically a 0Ω link (a jumper) used on PCBs. It behaves like a wire but is packaged like a resistor so automated pick-and-place machines can install it easily.
Reliability band (rare)
Some resistors made to military specifications include a band indicating failure rate (often specified as % per 1000 hours). This is uncommon in consumer electronics.
