3-Digit Code
The first two digits are the significant value and the third digit is the multiplier (a power of 10). This format is commonly used for both resistors and ceramic capacitors.
103 = 10 × 10³ → 10 kΩ or 10 nF
Identify & Decode SMD Markings
Decode common SMD markings and identify possible resistor or ceramic capacitor values.
Recent
Why can the same SMD code mean different things?
A three-digit marking is a compact way to encode a value, but it is used by more than one kind of component. A resistor reads the code as resistance in ohms; a ceramic capacitor reads the same three digits as capacitance in picofarads.
103
- Resistor
- 10 kΩ
- Ceramic capacitor
- 10 nF
Because both readings are valid, the marking alone does not tell you which component you are looking at. You need additional context to decide.
How to identify the actual component
- Component appearance — resistors and ceramic capacitors usually look different. Resistors are commonly flat and dark; ceramic capacitors are commonly a lighter tan or brown. Appearance is only a first hint.
- Package / physical size — note the part's footprint (for example 0402, 0603, 0805) and its thickness. This narrows the possibilities but does not confirm them.
- Circuit location — where the part sits is often the strongest clue. A capacitor next to a power pin is likely a decoupling capacitor; a resistor in series with a signal line is likely a series resistor.
- Multimeter measurement — measure it. A multimeter in resistance mode confirms a resistor; a capacitance meter confirms a capacitor.
Never identify a component by its SMD marking alone. Decode first, then verify.
How the codes work
4-Digit Code
The first three digits are the significant value and the fourth digit is the multiplier. This format is commonly used for precision resistors.
1002 = 100 × 10² → 10 kΩ
EIA-96 Code
Two digits plus one letter. The digits index a standard value table and the letter sets the multiplier. This format is commonly used for 1% tolerance resistors.
01C = 100 × 100 → 10 kΩ
These are commonly used marking conventions, not universal rules. Always cross-check against the component's datasheet when one is available.
FAQ
- What does 103 mean on an SMD component?
- 103 is a three-digit code: the first two digits (10) are the significant value and the third digit (3) is the multiplier (×10³). It reads as 10 kΩ for a resistor, or 10 nF (10,000 pF) for a ceramic capacitor.
- Is 103 a resistor or capacitor?
- The marking alone cannot tell you. 103 can be a 10 kΩ resistor or a 10 nF ceramic capacitor. Check the physical part, its location in the circuit, and measure it to confirm.
- What does 1002 mean on a resistor?
- 1002 is a four-digit precision resistor code: the first three digits (100) are the significant value and the fourth digit (2) is the multiplier (×10²). It means 10,000 Ω, or 10 kΩ.
- What is an EIA-96 code?
- EIA-96 is a commonly used marking convention for 1% tolerance resistors. It uses two digits plus one letter: the digits index a standard value table and the letter sets the multiplier. For example, 01C means 100 × 100 = 10 kΩ.
- Can an SMD marking identify a component by itself?
- No. The same marking can have different meanings depending on the component type — 103 is valid for both a resistor and a capacitor. Always confirm using appearance, package, circuit position, and measurement.