Decode the marking codes printed on surface-mount resistors and capacitors. Supports 3-digit, 4-digit, and EIA-96 marking systems.
Supports 3-digit, 4-digit, EIA-96, and R-notation codes.
The most common SMD resistor marking system. The first two digits are significant figures; the third digit is the multiplier (number of zeros to add).
| Code | Calculation | Value |
|---|---|---|
| 100 | 10 x 10^0 | 10 ohm |
| 221 | 22 x 10^1 | 220 ohm |
| 472 | 47 x 10^2 | 4.7 kohm |
| 103 | 10 x 10^3 | 10 kohm |
| 4R7 | R = decimal point | 4.7 ohm |
The letter "R" indicates the decimal point position. For example, "4R7" = 4.7 ohm, "R47" = 0.47 ohm.
Used on precision (1% tolerance) resistors. The first three digits are significant figures; the fourth digit is the multiplier.
| Code | Calculation | Value |
|---|---|---|
| 1001 | 100 x 10^1 | 1 kohm |
| 4702 | 470 x 10^2 | 47 kohm |
| 1000 | 100 x 10^0 | 100 ohm |
| 2201 | 220 x 10^1 | 2.2 kohm |
Used on 1% tolerance resistors, especially in smaller packages (0402, 0201). The code consists of two digits followed by a letter. The two digits map to a value in the EIA-96 lookup table; the letter indicates the multiplier.
| Letter | Multiplier |
|---|---|
| Z | 0.001 |
| Y or R | 0.01 |
| X or S | 0.1 |
| A | 1 |
| B or H | 10 |
| C | 100 |
| D | 1,000 |
| E | 10,000 |
| F | 100,000 |
Example: "01A" = 100 x 1 = 100 ohm. "68C" = 499 x 100 = 49.9 kohm (code 68 in EIA-96 = 499).
Most SMD capacitors (especially MLCCs in 0402/0603 sizes) have no marking at all. Larger sizes use a similar 3-digit code where the value is in picofarads (pF).
| Code | Value (pF) | Value |
|---|---|---|
| 101 | 100 pF | 100 pF |
| 104 | 100,000 pF | 100 nF (0.1 uF) |
| 224 | 220,000 pF | 220 nF (0.22 uF) |
| 475 | 4,700,000 pF | 4.7 uF |