Reverse Resistor Calculator

Enter any resistance value and instantly get the corresponding color code sequence. Perfect for when you know what value you need but can't remember which colors to look for in your parts bin.

🔄 Instant Conversion
📐 All Band Types
🎯 100% Accurate
Reverse Calculator

Enter resistance value to get color codes

Supported formats: 100, 4.7k, 1M, 2.2K, etc.

1st2nd×±

Supported Input Formats

Basic Values

100100Ω
10001kΩ
10000001MΩ

With Multipliers

4.7k4.7kΩ
2.2M2.2MΩ
100K100kΩ

Decimal Values

3.33.3Ω
15.8k15.8kΩ
0.10.1Ω

Pro Tip

The calculator is pretty forgiving with input formats. You can use uppercase or lowercase letters, include or omit the Ω symbol, and even add spaces. It'll figure out what you mean.

Important Things to Keep in Mind

Standard Values Only

This calculator shows you the color code for any value you enter, but remember that not all values are actually manufactured. Resistors come in standard series (E12, E24, E96) based on logarithmic spacing.

If you need an exact value that's not standard, you might need to use multiple resistors in series or parallel, or look into precision custom resistors.

Tolerance Assumptions

The calculator defaults to ±5% tolerance (gold band) for 4-band resistors and ±1% (brown band) for 5 and 6-band resistors. These are the most common tolerances, but other values are available.

For critical applications, always verify the tolerance you actually need and specify it when ordering components.