SMD Resistor Code Calculator
Decode 3-digit, 4-digit, R and EIA-96 surface-mount resistor markings.
About this tool
Type the marking printed on a surface-mount resistor and the calculator shows its value and which coding system it uses: 3-digit, 4-digit, R notation, EIA-96 or a zero-ohm jumper. Tap an example button to try common markings.
How to read SMD resistor codes
Surface-mount resistors are too small for colour bands, so they're printed with short numeric codes. The 3-digit code, used mostly on 5% tolerance parts, gives two significant digits and a multiplier: 103 is 10 × 1,000 = 10 kΩ and 472 is 4.7 kΩ. The 4-digit code, used on 1% parts, gives three significant digits and a multiplier: 1002 is 100 × 100 = 10 kΩ and 4702 is 47 kΩ. Small values use R to mark the decimal point, so 4R7 is 4.7 Ω and R22 is 0.22 Ω. On very small 1% resistors there's only room for three characters, so the EIA-96 system uses a two-digit index into the standard E96 value table plus a letter for the multiplier: 01C is entry 01 (100) × 100 = 10 kΩ, and 68X is entry 68 (499) × 0.1 = 49.9 Ω. A marking of 0 or 000 is a zero-ohm link used as a jumper. Honest limits: some manufacturers use proprietary codes, and the smallest packages, such as 0201 and 01005, usually carry no marking at all, so measure them with a multimeter or check the reel label. In-circuit measurements can be thrown off by parallel parts. The resistor colour code tool, the capacitor code calculator and the series and parallel resistor calculator are related.
Frequently asked questions
What does 103 mean on an SMD resistor?
10 followed by three zeros: 10,000 Ω, or 10 kΩ.
What is an EIA-96 resistor code?
A two-digit index into the E96 value table plus a multiplier letter, used on small 1% resistors; 01C is 10 kΩ.
What does R mean in a resistor code?
It marks the decimal point: 4R7 is 4.7 Ω and R10 is 0.1 Ω.
Is my data saved?
No. The decoding runs in your browser and nothing is stored or sent.