Resistor Color Code Calculator
Pick the color of each band to decode the resistance in ohms ($\Omega$, $\text{k}\Omega$, $\text{M}\Omega$) and tolerance range in real time.
How to read resistor color codes
Axial through-hole resistors use colored bands standardized under IEC 60062 to indicate their resistance value in ohms ($\Omega$) and manufacturing tolerance. Our interactive calculator updates the SVG resistor illustration in real time as you choose each band.
On a 4-band resistor, the first two rings represent the first two significant digits, the third ring is the decimal multiplier, and the fourth ring specifies tolerance. On a 5-band precision resistor, the first three rings are significant digits, the fourth is the multiplier, and the fifth is tolerance.
Usage example
Input bands (4-band): Brown (1) · Black (0) · Red ($\times 100$) · Gold ($\pm 5\%$).
Result: $10 \times 100 = 1000\text{ }\Omega = \mathbf{1\text{ k}\Omega \pm 5\%}$ (actual value between $950\text{ }\Omega$ and $1.05\text{ k}\Omega$).
Frequently Asked Questions
What are the color bands for a 1 kΩ and a 220 Ω resistor?
In 4-band ($\pm 5\%$) format, a 1 kΩ resistor is Brown - Black - Red - Gold. A 220 Ω resistor (commonly paired with LEDs) is Red - Red - Brown - Gold.
Which end of a resistor do you read first?
Hold the resistor with the gold or silver tolerance band on the right; there is also usually a slightly wider gap between the multiplier band and the tolerance band.
Why is the first band never black?
Black represents the digit 0, and significant numbers do not start with a leading zero (except special 0 Ω jumper resistors, which have a single centered black band).