How do I read a 3-digit SMD resistor code?

The first two digits are the significant figures and the third digit is the power-of-ten multiplier. For example, 103 means 10 times 10^3, which is 10,000 ohms or 10k ohms.

How do I read a 4-digit SMD resistor code?

The first three digits are the significant figures and the fourth digit is the multiplier. For example, 4702 means 470 times 10^2, which is 47,000 ohms or 47k ohms. 4-digit codes usually mark tighter-tolerance 1% resistors.

What does the letter R mean in a code like 4R7?

R stands in for the decimal point on resistors under 10 ohms, or under 100 ohms for 4-digit codes, since the digit-plus-multiplier format cannot show a decimal directly. 4R7 means 4.7 ohms and R47 means 0.47 ohms.

What is an EIA-96 code?

EIA-96 packs a 1% precision resistor value into 3 characters: two digits from 01 to 96 that index a table of significant figures, and a letter that sets the multiplier. For example, 01A means code 01, which is 100, times multiplier A, which is 1, equaling 100 ohms.

What does 000 or 0000 mean?

It marks a zero-ohm link, a jumper resistor used to bridge a trace, not an error in the code.

Does the code tell me the tolerance?

Not directly. By convention, 3-digit codes are typically 5% tolerance, 4-digit codes are typically 1%, and EIA-96 codes are always 1% or tighter. Check the datasheet for the exact part.

SMD Resistor Code

Decode an SMD resistor's printed code into its resistance value and tolerance, or look up the code for a target resistance.

Resistor code

103 → 3-digit: 10 × 10^3 = 10kΩ

4702 → 4-digit: 470 × 10^2 = 47kΩ

4R7 → R-notation: 4.7Ω

01A → EIA-96: 100 × 1 = 100Ω

Enter a code or a resistance value to see the result

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Summary

This calculator converts common SMD resistor markings into resistance and tolerance. It supports 3-digit, 4-digit, and EIA-96 formats, plus reverse lookup from a target resistance value.

How it works

Type the code printed on the resistor, such as 103, 4702, or 01A, into the Decode field.
The tool detects whether it is a 3-digit, 4-digit, or EIA-96 alphanumeric code and shows the resistance and typical tolerance.
Switch to Reverse Lookup, enter a target resistance and unit, and the tool generates matching 3-digit, 4-digit, and EIA-96 codes.
Click any result to copy it to your clipboard.

Use cases

Identify an unknown SMD resistor pulled from a board.
Verify a BOM value against the code printed on a component.
Find the correct EIA-96 code for a precision 1% resistor in a schematic.
Convert between 3-digit and 4-digit marking systems for a datasheet.
Check zero-ohm jumper markings such as 000 or 0000.
Teach SMD resistor coding conventions in an electronics class.

Frequently Asked Questions

Last updated: 2026-09-09 · Reviewed by Nham Vu

SMD Resistor Code

Use the SMD Resistor Code

Summary

How it works

Use cases

Frequently Asked Questions