Resistor Band Color Chart Calculator
This page supports decoding and encoding for 4-band, 5-band, and 6-band resistors. Use decode mode to turn band names into resistance values. Use encode mode to convert a resistance value into the nearest valid band combination.
The calculator also estimates minimum and maximum resistance from the selected tolerance. For 6-band resistors, it includes temperature coefficient information, which helps evaluate resistance drift as temperature changes.
Calculator Form
Example Data Table
| Type | Band Sequence | Decoded Value | Tolerance | Temp. Coefficient |
|---|---|---|---|---|
| 4 Band | Yellow, Violet, Red, Gold | 4.7 kΩ | ±5% | Not used |
| 5 Band | Brown, Black, Black, Red, Brown | 10 kΩ | ±1% | Not used |
| 6 Band | Orange, Orange, Black, Brown, Brown, Red | 3.3 kΩ | ±1% | 50 ppm/°C |
| Encode Example | 4700 Ω, 4 Band, ±5% | Yellow, Violet, Red, Gold | ±5% | Not used |
Resistor Band Reference Chart
| Color Name | Digit | Multiplier | Tolerance | Temp. Coefficient |
|---|---|---|---|---|
| Black | 0 | ×1 | — | 250 ppm/°C |
| Brown | 1 | ×10^1 | ±1% | 100 ppm/°C |
| Red | 2 | ×10^2 | ±2% | 50 ppm/°C |
| Orange | 3 | ×10^3 | — | 15 ppm/°C |
| Yellow | 4 | ×10^4 | — | 25 ppm/°C |
| Green | 5 | ×10^5 | ±0.5% | 20 ppm/°C |
| Blue | 6 | ×10^6 | ±0.25% | 10 ppm/°C |
| Violet | 7 | ×10^7 | ±0.1% | 5 ppm/°C |
| Gray | 8 | ×10^8 | ±0.05% | 1 ppm/°C |
| White | 9 | ×10^9 | — | — |
| Gold | — | ×10^-1 | ±5% | — |
| Silver | — | ×10^-2 | ±10% | — |
| Pink | — | ×10^-3 | — | — |
| None | — | — | ±20% | — |
Formula Used
4-Band: Resistance = (10 × first digit + second digit) × multiplier.
5-Band: Resistance = (100 × first digit + 10 × second digit + third digit) × multiplier.
6-Band: Use the 5-band formula, then apply the sixth band as temperature coefficient in ppm per degree Celsius.
Tolerance Range: Minimum = nominal × (1 − tolerance ÷ 100). Maximum = nominal × (1 + tolerance ÷ 100).
Temperature Drift Estimate: Change in resistance ≈ nominal × ppm × temperature change ÷ 1,000,000.
How to Use This Calculator
1. Choose decode mode to read resistor band names into an electrical value.
2. Choose encode mode to turn a resistance value into the nearest valid band set.
3. Select 4-band, 5-band, or 6-band format based on the resistor type.
4. Enter bands or resistance value, then choose tolerance and temperature coefficient where needed.
5. Press Calculate to view the result, tolerance range, graph, and export options.
FAQs
1. What does the resistor band calculator do?
It decodes band names into resistance values and also encodes resistance values back into likely band combinations for 4-band, 5-band, and 6-band resistors.
2. Why are 5-band resistors more precise?
They use three significant digits instead of two. That allows finer value representation before the multiplier is applied, which improves accuracy in reading precision resistors.
3. What does the tolerance band mean?
The tolerance band shows the allowed percentage variation from the nominal resistance. A 1 kΩ resistor with ±5% tolerance may measure between 950 Ω and 1050 Ω.
4. What is temperature coefficient in a 6-band resistor?
It shows how much resistance may change with temperature. The value is usually expressed in ppm per degree Celsius and matters in stable or precision circuits.
5. Can this page read gold and silver multiplier bands?
Yes. Gold and silver are supported as fractional multipliers, which is useful for low-value resistors and certain legacy resistor markings.
6. Why might encode mode show the nearest value?
Some resistance values cannot be represented exactly with the chosen number of significant digits and multiplier bands. In that case, the calculator shows the closest valid combination.
7. What does the Plotly graph display?
It compares minimum, nominal, and maximum resistance based on tolerance. This helps you quickly see the acceptable operating range for the selected resistor.
8. Can I export the result?
Yes. After calculation, you can download a CSV file for tabular use and a PDF file for sharing, saving, or documentation.