Precision Utility
Resistor Colour Code
Calculator
Supports
4/5/6 Band
Palette
Standard Colours
Decode any resistor colour code in seconds. Choose between 4, 5 or 6 band resistors, select the colours for each band and instantly see the resistance value, tolerance range and temperature coefficient. The visual resistor diagram updates in real time so you can verify your reading before soldering.
Band Selection
Resistor Preview
Resistance Value
1 kΩ
Resistance
1 kΩ
Tolerance
±5%
Min Value
950 Ω
Max Value
1.05 kΩ
How the resistor colour code calculator works
Start by choosing your band count. Most through-hole resistors use 4 bands, precision resistors use 5, and high-stability components use 6. The calculator adjusts its inputs automatically to match.
Select the colour for each band using the dropdowns. The first two (or three) bands represent significant digits. The multiplier band sets the power of ten. The tolerance band shows the accuracy of the component.
For 6-band resistors, the final band indicates the temperature coefficient in parts per million per degree Celsius (ppm/°C). Lower values mean the resistance stays more stable as temperature changes.
The resistor diagram updates in real time. The result card shows the nominal resistance, tolerance percentage, and the minimum and maximum actual resistance values you can expect from the component.
What you need to know about resistor colour codes
The resistor colour code is an international standard (IEC 60062) used to mark the resistance value, tolerance and sometimes temperature coefficient of fixed resistors. The system uses coloured bands painted around the component body.
Key points to remember:
- Always read bands from left to right, starting from the end with bands grouped closest together
- The tolerance band (gold, silver or a gap) is always the last band on the right
- Gold and silver only appear as multiplier or tolerance bands, never as digit bands
- Standard E12 series values (10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82) cover most applications
- Surface-mount resistors use a numeric code instead of colour bands
If you are building circuits regularly, learning the colour code by heart saves time. The mnemonic "Better Be Right Or Your Great Big Venture Goes Wrong" maps to Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White (digits 0–9).
Frequently asked questions
How do I read a resistor colour code?
Hold the resistor so the band grouping is on the left. Read the digit bands first (2 for 4-band, 3 for 5/6-band), then the multiplier band, then tolerance. Each colour represents a specific digit or multiplier value according to the international standard.
What is the difference between 4-band and 5-band resistors?
A 4-band resistor has two significant digit bands, one multiplier and one tolerance band. A 5-band resistor adds a third significant digit, giving higher precision. For example, 4-band can express 47 kΩ while 5-band can express 47.5 kΩ.
What does the gold band on a resistor mean?
Gold has two possible meanings depending on its position. As the multiplier band, gold means multiply by 0.1 (used for sub-10 Ω values). As the tolerance band, gold means the resistor's actual value is within ±5% of the stated resistance.
What is the tolerance band on a resistor?
The tolerance band indicates how much the actual resistance can deviate from the marked value. A 100 Ω resistor with gold (±5%) tolerance could measure anywhere from 95 to 105 Ω. Tighter tolerance (brown 1%, red 2%) costs more but gives more predictable circuit behaviour.
When do I need a 6-band resistor?
A 6-band resistor adds a temperature coefficient band that tells you how much the resistance changes with temperature. You need these in precision circuits, measurement equipment, or anywhere temperature stability matters. The sixth band is measured in parts per million per degree Celsius (ppm/°C).
How do I tell which end of the resistor to read from?
The tolerance band (gold, silver or a wider-spaced band) is always on the right. Group the remaining bands to the left and read from left to right. On 4-band resistors the gap between the third and fourth band is usually wider than the gaps between the first three.