SMD Resistor Calculator
Decode and generate SMD resistor codes – 3/4-digit codes, R notation and EIA-96
Decode code
47 kΩ
Mantissa 47 × 10^3 Ω.
Encode value
3-digit
4-digit
EIA-96
EIA-96: nearest E96 value is 4,75 kΩ.
Code systems
• 3-digit: Two mantissa digits + power of ten (473 = 47 × 10³ = 47 kΩ). Typical tolerance 5%.
• 4-digit: Three mantissa digits + power of ten (4702 = 470 × 10² = 47 kΩ). Typical tolerance 1%.
• R: R marks the decimal point (4R7 = 4.7 Ω, R22 = 0.22 Ω).
• EIA-96: Two digits as an index into the E96 series + a letter as multiplier (01A = 100 Ω, 68C = 49.9 kΩ).
Decode and Encode SMD Resistor Codes
Our tool provides a comprehensive way to decode and generate various SMD resistor codes used in electronic components. It supports standard three-digit codes, four-digit notations, the R decimal notation, and the EIA-96 system. Whether you are trying to identify a component on a PCB or need to calculate the correct marking for your design, this tool handles all common industry standards accurately. Simply enter your code or desired value to get instant results with clear explanations of the underlying calculations.
Support for Multiple Industry Standards
Engineers and hobbyists often encounter different labeling systems in manufacturing. This calculator simplifies the process by supporting three-digit codes (e.g., 473), four-digit codes (e.g., 4702), and the R notation where R indicates a decimal point. Additionally, it handles complex EIA-96 series calculations to find the nearest standard value. By providing clear conversions between physical markings and actual resistance values in Ohms, the tool helps prevent errors during component selection and assembly for your electronic projects.
Frequently asked questions
How do I interpret a three-digit SMD resistor code?
In a three-digit system, the first two digits represent the significant figures (mantissa), and the third digit represents the power of ten. For example, the code 473 translates to 47 multiplied by 10^3, resulting in 47kΩ. This is common for components with a typical tolerance of 5%.
What does a four-digit SMD resistor code like 4702 mean?
A four-digit code uses the first three digits as the mantissa and the fourth digit as the power of ten. For instance, 4702 means 470 multiplied by 10^2, which equals 47kΩ. These codes are typically used for components with a higher precision tolerance of 1%.
What is the EIA-96 standard for resistors?
The EIA-96 system uses two digits as an index into the E96 series followed by a letter representing the multiplier. For example, 01A corresponds to 100 Ω. This system allows for high-precision component selection in professional electronics manufacturing and design.
What does the R mean in resistor markings like 4R7?
The R notation is a convenient way to represent decimal points on small components where space is limited. In this system, the letter R acts as the decimal point. Therefore, a marking of 4R7 represents a resistance value of 4.7 Ohms.