Engineering Reference
Resistor Color Code Reference
Complete engineering reference for 4-band, 5-band and 6-band resistor color codes, tolerance bands and temperature coefficient values.
- Reading Time
- 8 min
- Difficulty
- Reference
- Last Updated
- July 11, 2026
Overview
Resistor color codes represent resistance value, multiplier, tolerance, and, for precision 6-band resistors, temperature coefficient. The system allows small cylindrical resistors to carry readable electrical data without printed text.
The color-band system is used internationally and is aligned with IEC 60062 marking conventions and common commercial resistor practice. It remains widely used because through-hole resistors are small, inexpensive, durable, and often handled in mixed inventory where visual identification is useful.
4-Band Reference
Band 1 and band 2 are significant digits. Band 3 is the multiplier. Band 4 is tolerance. A missing tolerance band is commonly treated as ±20% on older marking systems.
5-Band Reference
Band 1, band 2, and band 3 are significant digits. Band 4 is the multiplier and band 5 is tolerance. This format is common for precision resistors and values requiring three significant digits.
6-Band Reference
A 6-band resistor adds a temperature coefficient band after the tolerance band. The temperature coefficient is specified in ppm/°C and is typically used on precision and stability-critical parts.
Complete Color Code Table
Color meaning depends on band position. Gold and silver are not digit colors, but they are standard multiplier and tolerance colors.
| Color | Digit | Multiplier | Tolerance | Temperature Coefficient |
|---|---|---|---|---|
| Black | 0 | ×1 Ω | — | 250 ppm/°C |
| Brown | 1 | ×10 Ω | ±1% | 100 ppm/°C |
| Red | 2 | ×100 Ω | ±2% | 50 ppm/°C |
| Orange | 3 | ×1 kΩ | — | 15 ppm/°C |
| Yellow | 4 | ×10 kΩ | — | 25 ppm/°C |
| Green | 5 | ×100 kΩ | ±0.5% | 20 ppm/°C |
| Blue | 6 | ×1 MΩ | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10 MΩ | ±0.1% | 5 ppm/°C |
| Gray | 8 | ×100 MΩ | ±0.05% | 1 ppm/°C |
| White | 9 | ×1 GΩ | — | — |
| Gold | — | ×0.1 Ω | ±5% | — |
| Silver | — | ×0.01 Ω | ±10% | — |
Tolerance Reference Table
| Tolerance | Band | Typical Applications |
|---|---|---|
| ±1% | Brown | Precision signal paths, gain-setting networks, references, feedback dividers |
| ±2% | Red | General engineering use where moderate precision is acceptable |
| ±5% | Gold | General-purpose through-hole resistors, pull-ups, LED limiters, non-critical bias |
| ±10% | Silver | Legacy parts, rough biasing, non-critical current limiting |
| ±20% | No tolerance band | Older carbon composition parts and low-precision general use |
Temperature Coefficient Table
| Temperature Coefficient | Band | Typical Precision Use |
|---|---|---|
| 250 ppm/°C | Black | Low precision parts where temperature drift is not critical |
| 100 ppm/°C | Brown | General precision resistors and stable divider networks |
| 50 ppm/°C | Red | Precision analog circuits, references, and measurement equipment |
| 25 ppm/°C | Yellow | Higher stability resistor networks and instrumentation |
| 15 ppm/°C | Orange | Precision applications with tighter drift requirements |
| 10 ppm/°C | Blue | High stability references, filters, and measurement circuits |
| 5 ppm/°C | Violet | Very high stability precision resistors |
| 1 ppm/°C | Gray | Specialized precision and metrology-grade applications |
Engineering Notes
- Read direction usually starts from the band nearest one end.
- Damaged, faded, overheated, or dirty bands should be verified by measurement.
- Aging and thermal stress can shift resistance from nominal value.
- Precision resistors commonly use 5-band or 6-band markings.
- Surface mount resistors usually use numeric SMD codes instead of color bands.
Standards
IEC 60062 defines marking codes for resistors and capacitors, including color codes, letter codes, and related marking practices. Commercial resistor markings generally follow these conventions, although package size, manufacturer style, and product family can affect visual spacing and band placement.
Related Calculator
AvailableResistor Color Code Calculator
Decode 4-band, 5-band, and 6-band resistor bands into resistance, tolerance range, and temperature coefficient.
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Support reference
FAQ
What do resistor color bands represent?
Resistor color bands represent significant digits, a multiplier, tolerance, and on 6-band resistors, temperature coefficient.
Which standard defines resistor color codes?
IEC 60062 is the primary international standard covering marking codes for resistors and capacitors. Commercial parts also follow common industry conventions based on that system.
What is the difference between a 4-band and 5-band resistor?
A 4-band resistor uses two significant digit bands, while a 5-band resistor uses three significant digit bands before the multiplier and tolerance bands.
What does the sixth band mean on a resistor?
The sixth band identifies temperature coefficient in parts per million per degree Celsius, written as ppm/°C.
What does a gold band mean?
Gold indicates ×0.1 when used as a multiplier, or ±5% when used as the tolerance band.
What does a silver band mean?
Silver indicates ×0.01 when used as a multiplier, or ±10% when used as the tolerance band.
What tolerance is used when no tolerance band is present?
A missing tolerance band usually indicates ±20% on older or low-precision resistor marking systems.
Are resistor color codes used on surface mount resistors?
Most SMD resistors use printed numeric or alphanumeric codes instead of color bands, although the resistance value and tolerance concepts are the same.
Further Reading
- Engineering Reference hub and Resistor Reference category.
- IEC 60062 marking codes for resistors and capacitors.
- Resistor manufacturer datasheets for tolerance and temperature coefficient specifications.
- ECParts resistor calculators for applying color-code values in circuit checks.
- Engineering references covering preferred values, tolerance, drift, and power rating.