Need the ohms for a through-hole resistor without squinting at a faded color chart? Set the bands above, or type a value like 4.7k or 4k7, and copy the reading. Sizing a current-limiting resistor for an LED? Use the LED resistor calculator. This resistor color code calculator is part of the hardware tools on TechOpt.io.
How this resistor color code calculator reads bands
IEC 60062 color bands encode digits, a multiplier, a tolerance, and on some parts a temperature coefficient. Read from the end where the bands sit closer together. Gold and silver are never digits; they are multipliers (×0.1 and ×0.01) or tolerances (±5% and ±10%).
- 4-band: two digits, multiplier, tolerance. Typical of ±5% carbon-film parts. Brown-black-red-gold is 1 kΩ ±5%.
- 5-band: three digits, multiplier, tolerance. Typical of ±1% metal-film parts.
- 6-band: the 5-band code plus TCR in ppm/K, so you can see how the value drifts with heat.
Color code reference
| Color | Digit | Multiplier | Tolerance | TCR |
|---|---|---|---|---|
| Black | 0 | ×1 | 250 ppm/K | |
| Brown | 1 | ×10 | ±1% | 100 ppm/K |
| Red | 2 | ×100 | ±2% | 50 ppm/K |
| Orange | 3 | ×1 k | 15 ppm/K | |
| Yellow | 4 | ×10 k | 25 ppm/K | |
| Green | 5 | ×100 k | ±0.5% | 20 ppm/K |
| Blue | 6 | ×1 M | ±0.25% | 10 ppm/K |
| Violet | 7 | ×10 M | ±0.1% | 5 ppm/K |
| Grey | 8 | ×100 M | ±0.05% | 1 ppm/K |
| White | 9 | ×1 G | ||
| Gold | ×0.1 | ±5% | ||
| Silver | ×0.01 | ±10% |
FAQ
How do I read a 4-band resistor?
The first two bands are digits, the third is the multiplier, and the fourth is the tolerance. Brown-black-red-gold is 10 × 100 = 1 kΩ with ±5% tolerance. Start from the end where the bands sit closer together, opposite the gold or silver tolerance band.
What is the difference between 4-band, 5-band, and 6-band resistors?
A 4-band part has two digits, a multiplier, and a tolerance — typical of ±5% carbon-film resistors. A 5-band part adds a third digit for ±1% and tighter parts. A 6-band part adds a temperature coefficient (TCR) in ppm/K so you can see how the value drifts with heat.
What does gold or silver mean on a resistor?
On the multiplier band, gold means ×0.1 and silver means ×0.01, which covers values below 10 Ω on a 4-band code. On the tolerance band, gold is ±5% and silver is ±10%. Digit bands never use gold or silver.
How do I find the color code for a 4.7 kΩ resistor?
Type 4.7k or 4k7 in the calculator, or pick the 4.7 kΩ preset. A common 4-band ±5% code is yellow-violet-red-gold (47 × 100). A 5-band ±1% code is yellow-violet-black-brown-brown (470 × 10, ±1%).
Which end of the resistor do I start from?
Start at the end where the bands sit closer together. The last band is tolerance (often gold or silver, or a band spaced farther from the others). If both ends look similar, try both; the ohms reading should match the schematic or a meter.
Does this resistor calculator upload my values?
No. It runs entirely in your browser. Color bands and resistance values never leave your machine.
Looking for more calculators? Decode a ceramic cap with the capacitor code calculator, size an LED with the LED resistor calculator, or browse the rest of the tools.