Resistor Color Code
Decode resistor color bands
4/5/6 band support
Visual resistor
Color chart
You're holding a resistor with brown, black, orange, gold bands. Is that 10kΩ or 100Ω? You need a 4.7kΩ resistor from the bin—what colors are you looking for? The schematic says 220Ω but every resistor in your kit looks the same.
Resistor color codes pack a lot of information into tiny colored bands. Once you learn the system, you can identify any resistor instantly. This calculator decodes colors to values and encodes values to colors.
What is the Resistor Color Code?
The resistor color code is a standardized system using colored bands to indicate resistance value and tolerance. Each color represents a digit or multiplier, allowing identification without needing to measure.
The color values:
0: Black 5: Green
1: Brown 6: Blue
2: Red 7: Violet
3: Orange 8: Gray
4: Yellow 9: White
Multiplier bands:
Gold = ×0.1, Silver = ×0.01
Tolerance:
Brown = ±1%, Red = ±2%, Gold = ±5%, Silver = ±10%
"Bad Beer Rots Our Young Guts But Vodka Goes Well" = Black(0), Brown(1), Red(2), Orange(3), Yellow(4), Green(5), Blue(6), Violet(7), Gray(8), White(9).
Why People Actually Need This Tool
Resistors are too small for printed numbers. Color codes communicate value, tolerance, and sometimes temperature coefficient in a compact visual format.
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Component identification — Read resistor values from color bands.
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Parts selection — Find correct resistor from bulk storage.
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Circuit building — Verify you're using the right components.
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Troubleshooting — Confirm suspected resistor values without measuring.
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Inventory organization — Sort resistors by value quickly.
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Learning electronics — Understand the color coding system.
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Quality verification — Check if measured value matches coded value.
How to Use the Resistor Color Code Calculator
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Select bands — Choose 4, 5, or 6 band resistor type.
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Enter colors — Select color for each band.
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Read value — See resistance in ohms with tolerance.
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Or reverse — Enter value to see required colors.
| Bands | Configuration | Precision |
|---|---|---|
| 4 | Digit, Digit, Multiplier, Tolerance | Standard (±5%) |
| 5 | D, D, D, Multiplier, Tolerance | Precision (±1%) |
| 6 | D, D, D, Multiplier, Tolerance, TempCo | High precision |
Start reading from the band closest to the resistor's edge. Tolerance band (gold/silver) is usually at the end—start from the opposite end.
Real-World Use Cases
1. The Mystery Resistor
Context: Found resistor: Brown, Black, Red, Gold.
Problem: What's the value?
Solution: Brown(1), Black(0), Red(×100) = 1,000Ω = 1kΩ, ±5%.
Outcome: Resistor identified without measuring.
2. The Shopping List
Context: Need 4.7kΩ ±1% resistors for precision circuit.
Problem: What color bands to look for?
Solution: 5-band: Yellow(4), Violet(7), Black(0), Brown(×10), Brown(±1%) = 4.7kΩ.
Outcome: Correct resistors selected from catalog.
3. The Verification Check
Context: Built circuit doesn't work. Suspecting wrong resistor.
Problem: Is the 220Ω actually 220Ω?
Solution: 220Ω should be: Red(2), Red(2), Brown(×10), Gold(±5%).
Outcome: Discovered Red, Red, Red—that's 2.2kΩ, not 220Ω. Found the error.
4. The Bulk Bin Sort
Context: Inherited box of mixed resistors. Need to organize.
Problem: Sort thousands of resistors quickly.
Solution: Group by third band (multiplier): Browns together (×10), Reds (×100), Oranges (×1k).
Outcome: Organized inventory by value range.
5. The LED Calculation Follow-up
Context: Calculated 470Ω needed for LED circuit.
Problem: What does 470Ω look like?
Solution: Yellow(4), Violet(7), Brown(×10) = 470Ω.
Outcome: Correct resistor pulled from kit.
6. The Faded Resistor
Context: Old resistor with faded bands. Looks like Green-?-Orange-Gold.
Problem: What's the likely value?
Solution: Green(5), x, Orange(×1000) means 5x,000Ω range. Common values: 51k, 56k.
Outcome: Narrowed possibilities for verification.
7. The Precision Requirement
Context: Audio circuit spec says 10kΩ ±1%.
Problem: How to identify precision resistors?
Solution: 5-band with brown tolerance: Brown(1), Black(0), Black(0), Red(×100), Brown(±1%).
Outcome: Precision resistors distinguished from standard 5% versions.
Common Mistakes and How to Avoid Them
Reading bands backwards gives wrong value. Brown-Black-Red-Gold (1kΩ) read backwards is Gold-Red-Black-Brown—nonsense.
Privacy and Data Handling
This Resistor Color Code Calculator operates entirely in your browser.
- No calculations are sent to any server.
- No data is stored.
- No account required.
- Works completely offline.
Your electronics projects stay private.
Conclusion
Resistor color codes are a compact, standardized way to identify component values. Learning the system or using a calculator saves time and prevents circuit errors.
This calculator works both ways: enter colors to find value, or enter value to find colors. No more guessing, no more wrong components, no more failed circuits.
Decode the colors. Build with confidence.