Resistor Colour Code Calculator
Read a resistor from its bands, in 4, 5 or 6-band form.
How it works
The first bands are significant digits, the next is a power-of-ten multiplier, and the last is tolerance. Four bands give two digits, five and six give three, and the sixth band is a temperature coefficient.
Read from the end with the bands grouped closest together — the tolerance band sits slightly apart. If the colours are ambiguous, measure it: a meter settles in two seconds what squinting at a brown-versus-red band will not.
Common questions
Which end do I read from?
The end where the bands are bunched together. The tolerance band has a visibly wider gap before it. Gold or silver is almost always tolerance, so if you see one it goes last.
My resistor has no tolerance band.
Four visible bands with no gold or silver usually means a ±20% part, or you are looking at a five-band precision resistor. Measure it.