Select Bands
How the Bands Work
A 4-band resistor uses two significant digits, a multiplier, and tolerance. A 5-band resistor uses three significant digits, a multiplier, and tolerance.
Resistance = significant digits × multiplier
Example
Brown, black, red, gold is 10 × 100 = 1 kΩ ±5%. Its nominal tolerance range is 950 Ω to 1.05 kΩ.
Reading Direction
The tolerance band is usually separated from the other bands and is commonly gold, silver, brown, red, green, blue, violet, or gray. Hold that band to the right before reading.
Some precision, fusible, military, and temperature-coefficient markings use additional conventions outside this calculator.
Measure unknown resistors with power removed and at least one lead isolated when connected circuit paths could affect the reading.