Resistor Color Code Calculator
Free resistor color code calculator — decode 3, 4, 5, and 6-band resistors to resistance, tolerance, and temp coefficient with a live preview.
Everyday Uses
Bench reference
Decode any resistor from your parts drawer in seconds with the live visual preview.
Learning electronics
The interactive bands teach the color code faster than memorizing tables.
Repair verification
Confirm a replacement resistor matches the burnt one before soldering it in.
Sorting mixed parts
Bought an assorted resistor kit? Identify and label values without a multimeter.
Frequently Asked Questions
How do I read a resistor color code?
Hold the resistor with the tolerance band (usually gold or silver, set apart) on the right. On a 4-band resistor, the first two bands are digits, the third is the multiplier, the fourth is tolerance. Brown-Black-Red-Gold reads 1, 0, ×100 = 1,000 Ω (1 kΩ) at ±5%. 5-band precision resistors use three digit bands instead of two.
What do the colors stand for?
Black 0, Brown 1, Red 2, Orange 3, Yellow 4, Green 5, Blue 6, Violet 7, Grey 8, White 9. As multipliers they mean ×10 to the power of the digit; gold is ×0.1 and silver ×0.01. For tolerance: brown ±1%, red ±2%, green ±0.5%, gold ±5%, silver ±10%.
What does tolerance mean in practice?
The manufacturer's guaranteed accuracy. A 1 kΩ ±5% resistor actually measures between 950 and 1,050 Ω. For most hobby circuits ±5% is fine; precision analog circuits, voltage dividers for measurement, and audio applications often justify ±1% (5-band) resistors, which cost only slightly more.
Which end do I start reading from?
Start from the band nearest an end of the body; the tolerance band usually sits farther from its neighbors. If it's ambiguous, check plausibility: standard E-series values (1.0, 2.2, 4.7, 10, 22, 47…) are far more common — or simply measure with a multimeter, which settles it instantly.