SMD Resistor Code Calculator & Encoder

2025/5/28 16:21:01

SMD Resistor Code Calculator

SMD (Surface-Mount Device) resistors use a 3-digit or 4-digit code on their surface to show resistance. This calculator helps you find the resistance from these codes or get the correct code from a resistance value.

Use the tabs below to switch between decoding and encoding. Whether you are fixing a PCB, building a project, or checking a parts list, this tool helps you understand SMD resistor codes fast.

Enter SMD Resistor Code (3 or 4 digits):

Enter Resistance (e.g. 4.7k, 1000, 2.2M):

SMD Resistor Code Reference Table

Code	Resistance
100	10 Ω
472	4.7 kΩ
103	10 kΩ
1001	10 kΩ
104	100 kΩ
105	1 MΩ

Why do some resistors have more than one code? The code "103" (3-digit) and "1001" (4-digit) both mean 10 kΩ. They are different because of how exact they are. 4-digit codes are for 1% tolerance resistors. 3-digit codes are usually for 5% tolerance resistors.

How to read the codes: For a 3-digit code, the first two digits are the main number. The third digit tells how many zeros to add. For example, "472" means 47 plus two zeros = 4700 Ω or 4.7 kΩ. A 4-digit code like "1001" means 100 × 10^1 = 1000 Ω or 1 kΩ.

This page is part of our Electronics Tools. You can also try our color ring resistor calculator or LED Resistor Calculator.