Resistor Color Code Calculator: Read Resistor Values in Seconds
Decode resistor color bands instantly — 4-band, 5-band, and 6-band resistors. Learn the color code system with real examples and a handy reference table.
If you've ever held a tiny resistor up to the light and squinted at the colored bands trying to remember whether orange is 3 or 4, you're not alone. The color code system is one of those things that feels confusing until it clicks — and after that it's pretty intuitive. The CalcHub Resistor Color Code Calculator takes all the guesswork out of it.
What It Does
You pick the colors of each band from dropdown menus, and the calculator instantly tells you the resistance in ohms, kilohms, or megohms — plus the tolerance percentage. It handles 4-band, 5-band, and 6-band resistors.
The Color Code Table
Here's the reference you'll want to bookmark:
| Color | Digit | Multiplier | Tolerance |
|---|---|---|---|
| Black | 0 | ×1 | — |
| Brown | 1 | ×10 | ±1% |
| Red | 2 | ×100 | ±2% |
| Orange | 3 | ×1,000 | — |
| Yellow | 4 | ×10,000 | — |
| Green | 5 | ×100,000 | ±0.5% |
| Blue | 6 | ×1,000,000 | ±0.25% |
| Violet | 7 | ×10,000,000 | ±0.1% |
| Gray | 8 | ×100,000,000 | ±0.05% |
| White | 9 | ×1,000,000,000 | — |
| Gold | — | ×0.1 | ±5% |
| Silver | — | ×0.01 | ±10% |
How to Use the Calculator
- Count the bands on your resistor. Most through-hole resistors have 4 or 5 bands.
- Orient the resistor so the tolerance band (usually gold or silver) is on the right.
- Select each band color from left to right in the calculator.
- Read the result — resistance value and tolerance.
Tips That Save Time
The gap trick: On 5-band resistors, the tolerance band is often spaced slightly apart from the other four. That gap tells you which end to start reading from. Precision resistors: If you're working with metal film resistors (the blue ones), they're almost always 5-band with 1% tolerance. Carbon film resistors tend to be 4-band at 5%. When in doubt, measure: A multimeter set to resistance mode will always beat squinting at colors, especially when bands are faded or you're working under bad lighting. The memory shortcut: "Black Beer Rots Our Young Guts But Vodka Goes Well" — first letters map to Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White (0–9).Can I use this for SMD resistors?
SMD (surface-mount) resistors use a different system — usually a 3-digit or 4-digit number printed directly on the component. The color code calculator doesn't apply there. SMD resistors use codes like "103" meaning 10 × 10³ = 10kΩ.
What does the 6th band mean?
The 6th band represents the temperature coefficient, measured in ppm/°C. It tells you how much the resistance drifts with temperature changes — relevant in precision timing and measurement circuits, less so for general prototyping.
My resistor only has 3 bands — is that normal?
Yes, some older or very basic resistors have 3 bands where the tolerance is assumed to be ±20%. The calculator handles these too — just leave the tolerance band unselected.
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