FREE ENGINEERING CALCULATOR · BILINGUAL
SMD Resistor Code Calculator: 3-Digit, 4-Digit & EIA-96
Decode SMD resistor markings such as 103, 1002, 4R7 and 01C into resistance. Includes common examples, the complete 96-entry EIA-96 value table and multiplier letters.
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Calculated results
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| Nominal resistance | 121 Ω |
|---|
09A121 Ω
EIA-96 · 121 × 1 Ω
The code identifies nominal resistance, not necessarily tolerance, power rating or package size. Manufacturer-specific markings require the datasheet.
Calculation formulas
3-digit: first 2 digits × 10^last digit Ω. 4-digit: first 3 digits × 10^last digit Ω. EIA-96: table value × letter multiplier.
How do 103, 1002 and 100 differ?
103 = 10 × 10³ = 10 kΩ; 1002 = 100 × 10² = 10 kΩ; 100 = 10 × 10⁰ = 10 Ω. The last digit is an exponent, not another significant digit. A 100 marking therefore does not mean 100 Ω.
How do R markings differ from EIA-96 letters?
R is a decimal separator in low-value codes: 4R7 means 4.7 Ω and R22 means 0.22 Ω. EIA-96 instead looks up a two-digit index from 01 to 96 and applies a letter multiplier: 01C = 100 × 100 = 10 kΩ, while 10C = 124 × 100 = 12.4 kΩ.
Does 000 mean zero ohms?
This tool interprets 0, 00, 000 and 0000 as nominal zero-ohm jumpers. Real parts still have a small resistance and a current rating; mathematical zero resistance does not imply unlimited current capacity.
Can the marking prove 1% or 5% tolerance?
Not reliably. Marking conventions are associated with particular series, but different series can share a code scheme. Check the reel label or datasheet. Very small packages may be unmarked. Unrecognized codes are rejected rather than guessed.
Quick reference
| Y | X | A | B | C | D | E | F |
|---|---|---|---|---|---|---|---|
| × 0.01 | × 0.1 | × 1 | × 10 | × 100 | × 1000 | × 10000 | × 100000 |