Resistor Color Code Calculator
Choose the colours of the four bands to read the value.
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Resistor Color Code Calculator by TheCalcTools
How the Resistor Color Code Calculator works
Hold the resistor with the tolerance band (gold or silver) on the right.
The first two bands are digits, the third is the multiplier and the fourth is the tolerance.
Pick each colour here to see the value and the allowed range.
The formula
Worked example
Using the default values shown in the calculator:
| Band 1 (first digit) | Brown 1 |
|---|---|
| Band 2 (second digit) | Black 0 |
| Band 3 (multiplier) | Red ×100 |
| Band 4 (tolerance) | Gold ±5% |
- Brown, black, red, gold.
- Digits 1 and 0 make 10, times 10² gives 1,000 Ω, written 1.00 kΩ.
- With ±5% tolerance the actual value is between 950 and 1,050 Ω.
Result:
| Resistance (Ω) | 1,000.00 |
|---|---|
| Value | 1.00 kΩ |
| Minimum (Ω) | 950.00 |
| Maximum (Ω) | 1,050.00 |
Frequently asked questions
What if there are five bands?
Precision resistors use three digit bands, then a multiplier and a tolerance band. This calculator covers the common four-band type.
Which end do I read from?
Read from the end farthest from the tolerance band. Tolerance bands are usually gold or silver and are set slightly apart.
Sources and further reading
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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.