🎨 Resistor Color Code Calculator (4, 5, and 6 Band)
By Shihab Mia · Updated 2026-06-27
Pick a colour for each band to read the value.
| Colour | Digit | Multiplier | Tolerance | Temp. (ppm/K) |
|---|
This resistor color code calculator turns the coloured bands printed on a resistor into a clear resistance value in ohms. Choose 4, 5, or 6 bands, set the colour of each band, and read the resistance, the plus or minus tolerance range, and (for 6 band parts) the temperature coefficient. It is the fastest way to decode a resistor without memorising the colour chart.
What is the Resistor Color Code Calculator?
Resistors are too small to print numbers on, so manufacturers paint a series of coloured bands around the body to encode the value. Each colour stands for a number. The first bands are significant digits, the next band is a power of ten multiplier, and a band near the end gives the manufacturing tolerance. Reading them in the right order, from the end with the bands grouped together, gives you the nominal resistance and how far the real part may stray from it.
The digit colours run in the order of the visible spectrum, which makes them easier to remember: black is 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, and white 9. The multiplier band uses the same digit as a power of ten, so red as a multiplier means times 100. Two extra metallic colours appear only on the multiplier and tolerance bands: gold means times 0.1 (or 5 percent tolerance) and silver means times 0.01 (or 10 percent tolerance).
A 4 band resistor has two digit bands, a multiplier, and a tolerance band, so the value is (digit1 times 10 plus digit2) times the multiplier. A 5 band resistor adds a third significant digit for tighter, more precise values, giving (digit1 times 100 plus digit2 times 10 plus digit3) times the multiplier. A 6 band resistor is a 5 band resistor with one more band on the end that states the temperature coefficient in parts per million per kelvin, which tells you how much the resistance drifts as the part heats up.
The tolerance band matters as much as the digits. A 1000 ohm resistor at 5 percent tolerance may measure anywhere from 950 to 1050 ohms and still be in spec, while a 1 percent part stays within 990 to 1010 ohms. This calculator shows that range for you so you can decide whether a part is precise enough for a timing circuit, a voltage divider, or a current limiter before you solder it in.
When to use it
- Decoding a loose resistor from a parts drawer when the value is not written down anywhere.
- Checking that a 4, 5, or 6 band resistor matches the value a schematic or kit calls for.
- Seeing the real plus or minus range a tolerance band allows before using a part in a precision circuit.
- Reading the temperature coefficient of a 6 band resistor for designs that must stay stable as they warm up.
How to use the Resistor Color Code Calculator
- Choose whether your resistor has 4, 5, or 6 bands using the band count selector.
- Set the colour of each band in order, starting from the end where the bands are grouped together.
- Read the resistance in ohms, kilohms, or megohms along with the plus or minus tolerance range.
- For a 6 band part, note the temperature coefficient, then copy the full result if you need it.
Formula & method
Worked examples
A 4 band resistor with bands brown, black, red, gold.
- First digit brown = 1, second digit black = 0, so the digits read 10.
- Multiplier red = times 100.
- Resistance = 10 x 100 = 1000 ohms = 1 kilohm.
- Tolerance gold = plus or minus 5 percent, so the range is 950 to 1050 ohms.
Result: 1 kilohm at plus or minus 5 percent (950 ohms to 1.05 kilohms).
A 5 band precision resistor with bands brown, black, black, red, brown.
- Digits brown black black = 1, 0, 0, which read as 100.
- Multiplier red = times 100.
- Resistance = 100 x 100 = 10000 ohms = 10 kilohms.
- Tolerance brown = plus or minus 1 percent, so the range is 9.9 to 10.1 kilohms.
Result: 10 kilohms at plus or minus 1 percent (9.9 kilohms to 10.1 kilohms).
Colour values for digit and multiplier bands
| Colour | Digit | Multiplier |
|---|---|---|
| Black | 0 | x 1 |
| Brown | 1 | x 10 |
| Red | 2 | x 100 |
| Orange | 3 | x 1,000 |
| Yellow | 4 | x 10,000 |
| Green | 5 | x 100,000 |
| Blue | 6 | x 1,000,000 |
| Violet | 7 | x 10,000,000 |
| Grey | 8 | - |
| White | 9 | - |
| Gold | - | x 0.1 |
| Silver | - | x 0.01 |
Tolerance and temperature coefficient bands
| Colour | Tolerance | Temp. coeff. (ppm/K) |
|---|---|---|
| Brown | plus or minus 1% | 100 |
| Red | plus or minus 2% | 50 |
| Orange | - | 15 |
| Yellow | - | 25 |
| Green | plus or minus 0.5% | - |
| Blue | plus or minus 0.25% | 10 |
| Violet | plus or minus 0.1% | 5 |
| Grey | plus or minus 0.05% | - |
| Gold | plus or minus 5% | - |
| Silver | plus or minus 10% | - |
| None | plus or minus 20% | - |
Common mistakes to avoid
- Reading the bands from the wrong end. A resistor is read starting from the end where the bands sit closest together, leaving the wider gap before the tolerance band. Reading from the wrong end can flip a value completely, for example turning a 220 ohm part into a wildly different number.
- Confusing gold and silver multipliers with tolerance. Gold and silver appear on both the multiplier band and the tolerance band. As a multiplier they mean times 0.1 and times 0.01, but as the final band they mean 5 percent and 10 percent tolerance. Use the band position, not just the colour, to decide which role it plays.
- Mixing up a 4 band and a 5 band resistor. A 5 band part has three digit bands, not two, so it needs the three digit formula. Treating a 5 band resistor as a 4 band one (or the reverse) shifts the multiplier and gives a value that can be off by a factor of ten or more.
- Ignoring the tolerance range. The nominal value is only the centre of an allowed range. A 10 kilohm part at 10 percent tolerance can legitimately measure 9 to 11 kilohms, which can break a precision divider or timing circuit if you assumed an exact value.
Glossary
- Significant digit band
- A coloured band that represents one digit of the resistance value, from 0 (black) to 9 (white).
- Multiplier band
- The band that scales the digits by a power of ten, such as red for times 100, or gold for times 0.1.
- Tolerance band
- The band, often gold or silver, that states how far the real resistance may differ from the nominal value, as a plus or minus percentage.
- Temperature coefficient
- The sixth band on a 6 band resistor, giving how much the resistance changes per kelvin of temperature change, measured in parts per million per kelvin.
- Ohm
- The unit of electrical resistance. Larger values are written in kilohms (thousands) and megohms (millions).
- Nominal value
- The labelled or calculated centre resistance of a part, before the tolerance range is applied.
Frequently asked questions
How do I read a 4 band resistor color code?
Read the first two bands as digits, the third band as a power of ten multiplier, and the fourth band as the tolerance. For example brown, black, red, gold is 1, 0, times 100, plus or minus 5 percent, which is 1000 ohms (1 kilohm) at 5 percent.
What is the difference between 4, 5, and 6 band resistors?
A 4 band resistor has two digit bands, a multiplier, and a tolerance. A 5 band resistor adds a third digit band for more precision. A 6 band resistor is a 5 band part plus one more band giving the temperature coefficient in parts per million per kelvin.
Which end of the resistor do I start reading from?
Start from the end where the bands are grouped closer together. The tolerance band usually sits slightly apart from the others, often in gold or silver, and is read last. If both ends look similar, the gold or silver band marks the tolerance end.
What do gold and silver bands mean?
On the multiplier band gold means times 0.1 and silver means times 0.01, which give resistor values below ten ohms. On the final band gold means a tolerance of plus or minus 5 percent and silver means plus or minus 10 percent.
What does the tolerance percentage tell me?
It is the maximum amount the actual resistance may differ from the nominal value. A 1000 ohm resistor at 5 percent can measure 950 to 1050 ohms, while a 1 percent part stays within 990 to 1010 ohms. Tighter tolerance means a more predictable value.
Do all resistors use a color code?
Most through hole resistors use coloured bands, but small surface mount resistors usually print a short number code instead. This calculator is for the banded through hole type, which is the kind found in most kits, breadboards, and hand soldered projects.