🎨 Resistor Color Code Calculator
Select resistor color bands to calculate resistance (Ω) and tolerance.
Resistor Color Code Chart
| Color | Significant Digit | Multiplier | Tolerance | Temp. Coefficient (ppm/°C) |
|---|---|---|---|---|
| Black | 0 | ×1 | — | 250 |
| Brown | 1 | ×10 | ±1% | 100 |
| Red | 2 | ×100 | ±2% | 50 |
| Orange | 3 | ×1k | — | 15 |
| Yellow | 4 | ×10k | — | 25 |
| Green | 5 | ×100k | ±0.5% | 20 |
| Blue | 6 | ×1M | ±0.25% | 10 |
| Violet | 7 | ×10M | ±0.1% | 5 |
| Grey | 8 | ×100M | ±0.05% | 1 |
| White | 9 | ×1G | — | — |
| Gold | — | ×0.1 | ±5% | — |
| Silver | — | ×0.01 | ±10% | — |
What is a Resistor Color Code?
Color bands (stripes) printed on a resistor represent specific digits. A 4-band resistor uses 2 significant digits + multiplier + tolerance. A 5-band uses 3 significant digits + multiplier + tolerance. A 6-band adds a temperature coefficient.
How to Read Color Bands
The tolerance band (gold or silver) is on the right. Read bands from left to right and use the chart below to calculate the resistance value.
Color Mnemonic (Black Brown Red Orange Yellow Green Blue Violet Grey White)
Resistance Calculation Formula
Frequently Asked Questions
- What do gold and silver bands mean?
- Gold means ±5% tolerance and silver means ±10% tolerance. These bands are typically used only as tolerance bands.
- What is the difference between 4-band and 5-band resistors?
- A 4-band resistor uses 2 significant digits and a 5-band uses 3. Precision resistors typically use 5 or 6 bands.
- What does temperature coefficient (ppm/°C) mean?
- It indicates how much the resistance changes per 1°C temperature change. A smaller value means more temperature-stable resistance.
Worked examples
Brown, black, red and gold read as 1, 0, ×100 and ±5%, so the resistor is 10 × 100 = 1,000 Ω or 1 kΩ, between 950 Ω and 1,050 Ω.
A 5-band resistor with red, red, black, brown, brown is 220 × 10 = 2,200 Ω ±1%, and a 6-band part adds a temperature coefficient of 100 ppm/K.
What the reading assumes
The bands are read from the end that is closest to one lead, with the tolerance band usually separated by a wider gap. Values follow the E-series so the printed digits are always two or three significant figures. A five-band part is more precise than a four-band one, and a gold or silver multiplier means a fraction below 1 Ω.