Resistor Colour Code Calculator

Tap the colours on your resistor to see its value, tolerance and range, or type a value to find the colours. Works for 3, 4, 5 and 6-band resistors and for colour-coded inductors.

Grey is ±0.01% under IEC 60062:2016; some older parts use grey for ±0.05%.

A single black band marks a zero-ohm link (a jumper).

Find the colours for a value

Note: this is not a standard E-series value, so it may be hard to buy.

How to read a resistor colour code

Resistors are too small to print numbers on, so their value is shown with coloured bands. Each colour stands for a number from 0 to 9. Hold the resistor so the bands that are bunched together are on the left. The band standing on its own on the right, usually gold or silver, is the tolerance band.

• Read the first bands as digits. A 4-band resistor has two digit bands and a 5-band resistor has three.
• The next band is the multiplier: the number of zeros to add, or gold for divide by 10 and silver for divide by 100.
• The last band is the tolerance: how far the real value may be from the marked value.
• On a 6-band resistor the extra band at the end is the temperature coefficient in ppm per kelvin.

Resistor colour code chart

Values follow the international standard IEC 60062:2016. A popular way to remember the digit order is the phrase BB ROY of Great Britain had a Very Good Wife: Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White.

Worked examples

4-band: yellow, violet, orange, gold

Yellow is 4 and violet is 7, so the digits are 47. Orange is a multiplier of 1,000, giving 47,000 Ω or 47 kΩ. Gold means ±5%, so the real resistance lies between 44.65 kΩ and 49.35 kΩ.

5-band: brown, black, black, brown, brown

The three digits are 1, 0 and 0, which is 100. The brown multiplier is ×10, giving 1,000 Ω or 1 kΩ. The final brown band is a tolerance of ±1%, so the value is between 990 Ω and 1,010 Ω.

3-band: red, red, brown

The digits are 22 and brown multiplies by 10, so the value is 220 Ω. With no tolerance band the tolerance is ±20%.

Standard resistor values (E-series)

Resistors are made in preferred values called the E-series, defined in IEC 60063. The E12 series has 12 values in each decade (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) and suits ±10% parts, E24 suits ±5% parts and E96 suits ±1% parts. This calculator tells you when a reading is not a standard value, which usually means a colour was misread or the resistor was read from the wrong end.

Frequently Asked Questions

More tools: SMD Resistor Code, Ohm's Law Calculator and Series and Parallel Calculator.