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

The first two digits are significant figures and the third digit is the multiplier. For example, 103 means 10 × 10³ = 10,000 Ω.

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

The first three digits are significant figures and the fourth digit is the multiplier. For example, 1002 means 100 × 10² = 10,000 Ω.

What does R mean on an SMD resistor?

R usually marks the decimal point. For example, 4R7 means 4.7 Ω and R22 means 0.22 Ω.

What does 000 mean on an SMD resistor?

000 usually indicates a zero-ohm jumper, which is used like a removable link or PCB routing option.

What is EIA-96 resistor coding?

EIA-96 uses two digits for a preferred value table and one letter for the multiplier. It is commonly used for precision 1% SMD resistors.

Why does my resistor have no marking?

Very small packages such as 0201 or 01005 are often unmarked. Some manufacturers also omit markings on certain precision or low-value resistors.

Can this identify resistor tolerance?

Sometimes markings imply a system, but tolerance is not always printed. Check the datasheet or BOM when tolerance matters.

Should I verify with a meter?

Yes, especially for repair work or safety-critical circuits. Marking systems can vary, and in-circuit measurements may be affected by other components.

Engineering

SMD Resistor Code Calculator

Decode 3-digit, 4-digit, R-notation, jumper, and EIA-96 SMD resistor markings. Enter the printed code from a chip resistor and get the resistance value in ohms, kilohms, or megohms.

How SMD resistor codes work

Many chip resistors are too small for color bands, so manufacturers print short numeric or alphanumeric markings. The most common systems are 3-digit codes, 4-digit codes, R notation for decimals, and EIA-96 codes for precision values.

3-digit: 103 = 10 × 10³ = 10,000 Ω 4-digit: 1002 = 100 × 10² = 10,000 Ω R notation: 4R7 = 4.7 Ω EIA-96: 01C = 100 × 100 = 10,000 Ω

Common examples

Marking	Value	System
100	10 Ω	3-digit
103	10 kΩ	3-digit
1002	10 kΩ	4-digit
4R7	4.7 Ω	R notation
01C	10 kΩ	EIA-96

Important limitation

Very small chip resistors may have no marking at all, and some manufacturers use special markings. If the result is critical, verify with a multimeter, BOM, schematic, or manufacturer datasheet.

Trusted references

For non-competitor background on chip-resistor marking, see TT Electronics – Resistor Marking Codes, KOA – resistor markings, and Yageo – chip resistor marking guide.

Common questions

The first two digits are significant figures and the third digit is the multiplier. For example, 103 means 10 × 10³ = 10,000 Ω.
The first three digits are significant figures and the fourth digit is the multiplier. For example, 1002 means 100 × 10² = 10,000 Ω.
R usually marks the decimal point. For example, 4R7 means 4.7 Ω and R22 means 0.22 Ω.
000 usually indicates a zero-ohm jumper, which is used like a removable link or PCB routing option.
EIA-96 uses two digits for a preferred value table and one letter for the multiplier. It is commonly used for precision 1% SMD resistors.
Very small packages such as 0201 or 01005 are often unmarked. Some manufacturers also omit markings on certain precision or low-value resistors.
Sometimes markings imply a system, but tolerance is not always printed. Check the datasheet or BOM when tolerance matters.
Yes, especially for repair work or safety-critical circuits. Marking systems can vary, and in-circuit measurements may be affected by other components.