What do numbers on SMD resistors mean?

They encode resistance value using short markings. Common formats are 3-digit, 4-digit, and EIA-96.

How do I calculate resistance from a 3-digit code?

The first two digits are significant, and the third digit is the multiplier power of ten. Example: 103 = 10 × 10^3 = 10 kΩ.

What is EIA-96 on SMD resistors?

EIA-96 uses two digits plus one letter for 1% resistors. The two digits map to a base value and the letter sets a multiplier.

SMD Resistor Code Calculator

Decode resistor markings and calculate resistance from 3-digit, 4-digit, and EIA-96 SMD codes.
The calculator runs entirely in your browser.

SMD Code

Result

Resistance
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Code Type
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Tolerance
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Common SMD Resistor Codes

Code	Resistance	Note

EIA-96 Multiplier Letters

What the numbers on SMD resistors mean

SMD resistor markings are compact codes for resistance values. Most chips use either a numeric format (3-digit or 4-digit) or EIA-96 (two digits plus one letter). Once you identify the format, converting the code to ohms is straightforward.

3-digit code

First 2 digits = significant value, last digit = multiplier.

Example: 103 → 10 × 10³ = 10,000 Ω (10 kΩ)

4-digit code

First 3 digits = significant value, last digit = multiplier.

Example: 1001 → 100 × 10¹ = 1,000 Ω (1 kΩ)

EIA-96 code

Two digits map to a base value (01-96), letter defines multiplier.

Example: 01C → 100 × 100 = 10,000 Ω (10 kΩ)

FAQ

How do I calculate resistance from SMD markings?

Identify the code type first, then apply the matching rule. Numeric codes use powers of ten, while EIA-96 uses a lookup base plus a letter multiplier.

Why does the tolerance differ?

3-digit markings are often associated with wider tolerance (commonly ±5%), while 4-digit and EIA-96 are typically used for tighter tolerance parts (commonly ±1%). Manufacturer rules still apply.