Resistor Color Code Calculator: 4-Band & 5-Band
Select the band colors to calculate resistance value, multiplier, and tolerance with an interactive visual preview.
How to Use the Resistor Color Code Calculator
This calculator decodes both 4-band standard resistors and 5-band precision resistors into exact resistance and tolerance values:
- Select Band Mode: Click 4-Band for standard hobbyist carbon film or metal film resistors, or 5-Band for high-precision resistors with three significant digits.
- Choose Color Bands: Select the matching colors from your physical resistor. Start from the band closest to one edge of the resistor body. The calculator automatically updates the live resistor graphic to reflect your choices.
- Read Resistance and Tolerance: The computed resistance appears immediately formatted in ohms (Ω), kilohms (kΩ), megohms (MΩ), or gigohms (GΩ), alongside the tolerance percentage band range.
Standard Resistor Color Code Reference Chart
The international standard IEC 60062 assigns specific numeric values, multipliers, and tolerance percentages to individual color bands. The complete reference chart is outlined below:
| Color | Digit 1 & 2 (4-Band) | Digit 3 (5-Band) | Multiplier | Tolerance | Temp. Coefficient |
|---|---|---|---|---|---|
| Black | 0 | 0 | × 1 Ω | (None) | 250 ppm/K |
| Brown | 1 | 1 | × 10 Ω | ± 1% | 100 ppm/K |
| Red | 2 | 2 | × 100 Ω | ± 2% | 50 ppm/K |
| Orange | 3 | 3 | × 1 kΩ | ± 0.05% | 15 ppm/K |
| Yellow | 4 | 4 | × 10 kΩ | ± 0.02% | 25 ppm/K |
| Green | 5 | 5 | × 100 kΩ | ± 0.5% | 20 ppm/K |
| Blue | 6 | 6 | × 1 MΩ | ± 0.25% | 10 ppm/K |
| Violet | 7 | 7 | × 10 MΩ | ± 0.1% | 5 ppm/K |
| Grey | 8 | 8 | × 100 MΩ | ± 0.01% | 1 ppm/K |
| White | 9 | 9 | × 1 GΩ | (None) | (None) |
| Gold | (None) | (None) | × 0.1 Ω | ± 5% | (None) |
| Silver | (None) | (None) | × 0.01 Ω | ± 10% | (None) |
How Resistor Formulas Work: 4-Band vs 5-Band Calculations
Calculating resistance from color bands relies on simple sequential multiplication:
4-Band Resistor Formula
A 4-band resistor consists of two significant digit bands, one multiplier band, and one tolerance band:
Example 4-Band Calculation:
- Band 1: Brown (value = 1)
- Band 2: Black (value = 0)
- Band 3 (Multiplier): Brown (multiplier = 10)
- Band 4 (Tolerance): Gold (± 5%)
- Calculation: (10) × 10 = 100 Ω with ± 5% tolerance (95 Ω to 105 Ω range).
5-Band Resistor Formula
A 5-band precision resistor provides three significant digit bands before applying the multiplier:
Example 5-Band Calculation:
- Band 1: Brown (value = 1)
- Band 2: Black (value = 0)
- Band 3: Black (value = 0)
- Band 4 (Multiplier): Brown (multiplier = 10)
- Band 5 (Tolerance): Brown (± 1%)
- Calculation: (100) × 10 = 1,000 Ω (1 kΩ) with ± 1% tolerance (990 Ω to 1,010 Ω range).
Common Resistor Values Quick Reference Table
Below is a handy reference table of frequently used resistor values across electronics prototyping, microcontrollers (Arduino, ESP32, Raspberry Pi), and audio circuits:
| Nominal Value | 4-Band Color Sequence (± 5% Gold) | 5-Band Color Sequence (± 1% Brown) | Common Application |
|---|---|---|---|
| 10 Ω | Brown, Black, Black, Gold | Brown, Black, Black, Gold, Brown | Current sensing, speaker outputs |
| 100 Ω | Brown, Black, Brown, Gold | Brown, Black, Black, Black, Brown | LED current limiting (5V high brightness) |
| 220 Ω | Red, Red, Brown, Gold | Red, Red, Black, Black, Brown | Standard 5V LED indicator protection |
| 330 Ω | Orange, Orange, Brown, Gold | Orange, Orange, Black, Black, Brown | Standard 3.3V LED indicator protection |
| 470 Ω | Yellow, Violet, Brown, Gold | Yellow, Violet, Black, Black, Brown | Optocoupler input drive, base resistor |
| 1 kΩ (1,000 Ω) | Brown, Black, Red, Gold | Brown, Black, Black, Brown, Brown | BJT transistor base drive, voltage dividers |
| 4.7 kΩ (4,700 Ω) | Yellow, Violet, Red, Gold | Yellow, Violet, Black, Brown, Brown | I2C bus pull-up lines (SDA/SCL) |
| 10 kΩ (10,000 Ω) | Brown, Black, Orange, Gold | Brown, Black, Black, Red, Brown | Microcontroller reset and button pull-ups |
| 30 kΩ (30,000 Ω) | Orange, Black, Orange, Gold | Orange, Black, Black, Red, Brown | Amplifier feedback networks, bias circuits |
| 100 kΩ (100,000 Ω) | Brown, Black, Yellow, Gold | Brown, Black, Black, Orange, Brown | Op-amp high-impedance inputs, timing circuits |
| 1 MΩ (1,000,000 Ω) | Brown, Black, Green, Gold | Brown, Black, Black, Yellow, Brown | Oscillator crystals, megohm bleeder circuits |
Standard Resistor Series: E12, E24, and E96 Explained
Resistors are not manufactured in arbitrary values. Instead, they adhere to standardized preferred number series defined by the International Electrotechnical Commission (IEC):
- E12 Series (10% Tolerance): Provides 12 values per decade (1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2).
- E24 Series (5% Tolerance): Adds 12 intermediate values per decade (including 1.1, 1.3, 1.6, 2.0, 2.4, 3.0, 3.6, 4.3, 5.1, 6.2, 7.5, 9.1).
- E96 Series (1% Precision): Features 96 logarithmic steps per decade, standard for 5-band metal film resistors in precision instrumentation.
Practical Tips for Reading Physical Resistors
Reading real-world components can sometimes be tricky under fluorescent workshop lamps. Keep these practical rules in mind:
- Find the Gap: The tolerance band (gold, silver, or brown) is separated by a visibly wider gap from the numeric bands. Always position this gap to the right before reading from left to right.
- Resolving Ambiguous Colors: Red and orange, or violet and blue, can look similar on darker ceramic coatings. Check both interpretations against the E24 standard value list; only one combination is typically a standard commercial value.
- Verify with a Digital Multimeter: When working with burnt or heat-stressed resistors where band colors have faded, verify resistance using a digital multimeter set to resistance mode.
Integrating with Ohm's Law and Circuit Analysis
Once you determine the component resistance, calculate circuit voltage drops, current draw, and power dissipation using our companion Ohm's Law Calculator. Knowing whether your resistor dissipates 0.1W or 0.8W helps ensure you choose the appropriate 1/4-watt, 1/2-watt, or 1-watt physical size.
Frequently Asked Questions
Which direction do I read resistor color bands?
Read starting from the band nearest to one outer lead edge toward the other. The tolerance band (often gold, silver, brown, or red) is positioned further apart from the numeric digit bands and represents the final band.
What is the difference between a 4-band and 5-band resistor?
A 4-band resistor uses two digit bands, one multiplier band, and one tolerance band. A 5-band resistor provides three significant digit bands before the multiplier, offering higher precision and tighter tolerance ratings.
What does resistor tolerance percentage mean?
Tolerance indicates how much the physical component resistance can deviate from its nominal marked rating. For example, a 100 ohm resistor with plus or minus 5% tolerance can measure between 95 ohms and 105 ohms.
What does a 3-band resistor mean when no tolerance band is present?
Vintage or older 3-band resistors without an explicit tolerance band default to a standard plus or minus 20% tolerance rating. Modern components generally have 4, 5, or 6 bands.
What is the sixth band on a 6-band resistor?
The sixth band specifies the temperature coefficient of resistance (TCR), measured in parts per million per Kelvin (ppm/K), indicating how much resistance shifts as operating temperature changes.
How do I calculate resistor color codes in reverse from resistance in ohms?
Extract the first two or three leading digits for the color digit bands, then choose the power of 10 multiplier color that scales the digits to your target resistance, followed by your desired tolerance band.