Resistor Color Code Calculator
Pick the colour of each band to read the resistance, tolerance, the range it can really measure, and the nearest standard E-series value. Choose the number of bands, set the colours, then press Read value. The URL keeps your choice, so you can share it.
Result
1-0 × 10¹ = 100 Ω, ±5%
| Quantity | Value |
|---|---|
| Resistance | 100 Ω ±5% |
| Range | 95 Ω to 105 Ω |
| Nearest E24 value | 100 Ω |
The tolerance band is the lone band at one end, usually gold or silver and slightly separated. Read from the end nearest the banded group. Always confirm with a meter for precision work.
Color chart
Print this page for the bench: the chart below is plain text and prints cleanly.
| Color | Digit | Multiplier | Tolerance | TCR |
|---|---|---|---|---|
| black | 0 | ×10⁰ | — | 250 ppm |
| brown | 1 | ×10¹ | ±1% | 100 ppm |
| red | 2 | ×10² | ±2% | 50 ppm |
| orange | 3 | ×10³ | — | 15 ppm |
| yellow | 4 | ×10⁴ | — | 25 ppm |
| green | 5 | ×10⁵ | ±0.5% | 20 ppm |
| blue | 6 | ×10⁶ | ±0.25% | 10 ppm |
| violet | 7 | ×10⁷ | ±0.1% | 5 ppm |
| grey | 8 | ×10⁸ | ±0.05% | 1 ppm |
| white | 9 | ×10⁹ | — | — |
| gold | — | ×0.1 | ±5% | — |
| silver | — | ×0.01 | ±10% | — |
Mnemonic
Better Be Right Or Your Great Big Vault Goes Wrong: Black Brown Red Orange Yellow Green Blue Violet Grey White = 0 through 9.
Worked examples
| Bands | Reading | Result |
|---|---|---|
| Red Brown Black Gold (4) | 2-1 ×10⁰ ±5% | 21 Ω ±5%, nearest E24: 22 Ω |
| Brown Black Orange Gold (4) | 1-0 ×10³ ±5% | 10 kΩ ±5% |
| Yellow Violet Red Silver (4) | 4-7 ×10² ±10% | 4.7 kΩ ±10% |
| Brown Black Black Brown Brown (5) | 1-0-0 ×10¹ ±1% | 1 kΩ ±1% |
| Orange Orange Black Black Red Red (6) | 3-3-0 ×10⁰ ±2%, 50 ppm | 330 Ω ±2%, 50 ppm/°C |
FAQ
What do red, brown, black, gold mean?
Red is 2, brown is 1, black is 0, so 21 × 10⁰ = 21 Ω, and gold is ±5%. The range is 19.95 to 22.05 Ω; the nearest standard value is 22 Ω.
Which side is the tolerance band?
The lone band at one end, usually gold or silver and slightly separated from the rest. Read from the end closest to the banded group.
How do I read a 5-band resistor?
Three digit bands, then the multiplier, then the tolerance: 1-0-0 ×10¹ = 1000 Ω. 5-band parts are typically 1% metal film.
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