Resistor Color Code Calculator
Pick the color of each band and read off a resistor's resistance and tolerance.
How it works
Through-hole resistors carry their value as a ring of colored bands. Each color maps to a digit — black is 0, brown 1, red 2, and so on up to white at 9 — following the classic order most people learn as a mnemonic.
The first two bands (or first three, on a five-band resistor) spell out the significant digits. The next band is a multiplier: it tells you what power of ten to scale those digits by, with gold and silver handling fractional multipliers below one ohm.
The last band is tolerance — how far the real resistance can wander from the printed value. Gold means ±5%, silver ±10%, and the tighter brown and red bands mean ±1% and ±2%. Set each dropdown to match your resistor and the value updates as you go.
Frequently asked questions
How do I know which end to read from?
The tolerance band is usually the odd one out — gold, silver, or set slightly apart from the rest. Put that band on the right, and read the color bands from left to right.
What's the difference between 4 and 5 band?
A five-band resistor adds a third significant digit for extra precision, so the reading is more exact. Four-band parts are the common general-purpose resistors you find in most kits.
Why does my resistor show gold as a multiplier?
Gold and silver in the multiplier position mean ×0.1 and ×0.01, which is how manufacturers mark sub-one-ohm resistors used in current sensing and similar spots.