Resistor Color Code Calculator
Read a 4-, 5- or 6-band resistor’s value, tolerance and temperature coefficient from its colours, or find the bands for a value, with the nearest standard E-series value.
Result…
How it's calculated
4 bands: digit digit × multiplier, tolerance 5 bands: digit digit digit × multiplier, tolerance 6 bands: as 5, plus temperature coefficient (ppm/K) Resistance = digits × 10^multiplier exponent Range = value × (1 ± tolerance ÷ 100)
The first two or three bands are digits (black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9). The next band multiplies by a power of ten, the same colours, plus gold ×0.1, silver ×0.01 and pink ×0.001. Then the tolerance: brown ±1%, red ±2%, green ±0.5%, blue ±0.25%, violet ±0.1%, orange ±0.05%, yellow ±0.02%, grey ±0.01%, gold ±5%, silver ±10%, and ±20% with no band. A sixth band is the temperature coefficient in ppm/K. These are the IEC 60062 meanings. Standard values follow the IEC 60063 E series that matches the tolerance (E24 for ±5%, E96 for ±1%).
Your numbers, step by step
About the Resistor Color Code calculator
This resistor colour code calculator reads the coloured bands on a through-hole resistor and gives its resistance, tolerance and, for six-band parts, the temperature coefficient in ppm/K. It works the other way too: type a value such as 4.7 kΩ and it lists the bands to look for, rounding to the two or three digits the band count allows. Both directions also give the lowest and highest resistance within tolerance and the nearest standard value from the E series that matches the tolerance, such as E24 for ±5% or E96 for ±1%. Hobbyists sorting a parts drawer, electronics students and repair technicians use it. The colours follow the IEC 60062 code, as set out in the electronic colour code table, and the steps show each digit and the multiplier.
How to use it
- Choose the “Direction”: “Colours → value” to read a resistor, or “Value → colours” to find the bands.
- Pick the “Number of bands”: 4 bands have two digits, 5 and 6 bands have three.
- Holding the resistor with the bunched bands on the left, set the “1st band (digit)”, “2nd band (digit)”, any “3rd band (digit)” and the “Multiplier band”.
- Set the “Tolerance band”, and for six bands the “Temperature coefficient band”.
- Read the resistance, the range it may fall in, and the nearest standard E-series value.
Worked example
A four-band resistor reads yellow, violet, red, gold. Yellow is 4 and violet is 7, giving 47; red multiplies by 100, so the value is 47 × 100 = 4,700 Ω, or 4.7 kΩ. Gold is ±5%, so it may measure anywhere from 4,465 Ω to 4,935 Ω, and 4.7 kΩ is a standard E24 value. Going the other way, 3.3 kΩ ±1% on five bands is orange, orange, black, brown, brown.
Updated
Questions people ask
How do I read a resistor colour code?
Start from the end where the bands are bunched together. The first two (or three) bands are digits, the next is the power of ten to multiply by, and the band set apart is the tolerance.
Which end of the resistor do I start from?
The tolerance band, often gold or silver, is usually a little apart from the rest and goes on the right. Gold and silver are never digit colours, so a resistor can't start with them.
What does a sixth band mean?
On six-band resistors the last band is the temperature coefficient: how much the resistance drifts per kelvin, in parts per million. Brown is 100 ppm/K and red 50 ppm/K.
Why does the calculator say my value is not in the E series?
Resistors are made in preferred values that depend on the tolerance: E24 for ±5% and E96 for ±1%. If a reading such as 4.8 kΩ is not one of them, a band has probably been misread, so check the colours or measure it.
Can the colours be read wrongly?
Yes. Red, orange and brown look alike under poor light, and older or unusual parts don't always follow IEC 60062. When it matters, measure with a meter, and work out current and voltage with the Ohm's law calculator.