Electronics · Free Calculator
SMD Resistor Code Calculator
Type the code printed on a surface mount resistor to get its resistance. Works with 3 digit, 4 digit, R decimal and EIA 96 marking.
3 digit (472)4 digit (1002)R notation (4R7)EIA 96 (01C)
Resistance4.7 kΩ
Code type3 digit
Typical toleranceusually ± 5 %
How this result was calculated
- 47 × 10^2 = 4.7 kΩ
Advertisement
How SMD Resistor Codes Work
Surface mount resistors are too small for colour bands, so the value is printed as a short code.
3 digit: R = AB × 10^C (472 = 47 × 10² = 4.7 kΩ)
4 digit: R = ABC × 10^D (1002 = 100 × 10² = 10 kΩ)
R notation: R is the decimal point (4R7 = 4.7 Ω)
EIA 96: two digit index into the E96 table plus a multiplier letter (01C = 100 × 100 = 10 kΩ)
4 digit: R = ABC × 10^D (1002 = 100 × 10² = 10 kΩ)
R notation: R is the decimal point (4R7 = 4.7 Ω)
EIA 96: two digit index into the E96 table plus a multiplier letter (01C = 100 × 100 = 10 kΩ)
EIA 96 multiplier letters: Z × 0.001, Y or R × 0.01, X or S × 0.1, A × 1, B or H × 10, C × 100, D × 1000, E × 10,000, F × 100,000.
Worked example
A resistor marked 103 is 10 × 10³ = 10 kΩ. One marked 4701 is 470 × 10¹ = 4.7 kΩ. One marked 68X is 499 × 0.1 = 49.9 Ω.
Key insight: 3 digit codes are normally 5 % parts, while 4 digit and EIA 96 codes mark 1 % precision parts, so the code style alone tells you the tolerance class.
Advertisement
Frequently Asked Questions
What does 103 mean on an SMD resistor?
10 followed by three zeros, so 10,000 Ω or 10 kΩ.
What is the value of a 4R7 SMD resistor?
4.7 Ω. The R marks the decimal point.
What does 01C mean on a resistor?
It is an EIA 96 code. 01 is 100 in the E96 table and C is × 100, giving 10 kΩ.
You May Also Like
Learn more on the blog
Resistor types explained
A practical, field focused guide on instrumentationblog.in that explains the theory behind this calculator and how engineers apply it on real plants.
Read Full ArticleMore Electronics Calculators
Capacitor Code Calculator3 digit code, Tolerance letterStandard Resistor Values Calculator (E Series)E6 and E12, E24 (5 %)Inductors in Series and Parallel CalculatorSeries, ParallelAir Core Coil Inductance CalculatorWheeler formula, Single layer coilResistor Power Rating CalculatorP = V²/R, P = I²RCurrent Divider CalculatorTwo or three branches, Branch currentWheatstone Bridge CalculatorBalance condition, Output voltageRC and RL Filter Cutoff Frequency CalculatorLow pass, High passRLC Circuit Impedance CalculatorSeries RLC, Parallel RLCLED Series and Parallel Array CalculatorLEDs per string, String resistorTransistor Base Resistor CalculatorBJT switch, SaturationInverting Op Amp Amplifier CalculatorGain = −Rf/Rin, Output voltageNon Inverting Op Amp Amplifier CalculatorGain = 1 + Rf/Rg, Output voltageOp Amp Differential Amplifier CalculatorVout = (R2/R1)(V2 − V1), Four resistorsOp Amp Summing Amplifier CalculatorOp amp adder, Weighted sumInstrumentation Amplifier Gain Resistor CalculatorAD620, AD8221, INA128, INA333Op Amp Gain Bandwidth and Slew Rate CalculatorGBW ÷ gain, Slew rate555 Timer Astable CalculatorFrequency, Duty cycle555 Timer Monostable Calculatort = 1.1 RC, One shotCrystal Load Capacitor CalculatorC1 = C2, Load capacitanceFrequency to Period CalculatorHz to seconds, Period to HzPWM Duty Cycle CalculatorDuty cycle %, Average voltageLM317 Voltage Regulator CalculatorVout = 1.25(1 + R2/R1), R2 for targetZener Diode Series Resistor CalculatorSeries resistor, Zener powerLinear Regulator Power Dissipation CalculatorPower dissipation, Junction temperatureHeat Sink Thermal Resistance CalculatorθSA in °C/W, Junction temperatureBuck Converter CalculatorDuty cycle, Inductor valueBoost Converter CalculatorDuty cycle, Inductor valueRectifier Filter Capacitor CalculatorSmoothing capacitor, Ripple voltagePCB Trace Width Calculator (IPC 2221)IPC 2221, External and internalPCB Trace Resistance CalculatorCopper resistance, Voltage dropBinary, Decimal, Hex and Octal ConverterBinary, HexadecimalBattery Life Calculator for Electronic DevicesmAh capacity, Sleep currentdBm to Watts CalculatordBm to mW, Watts to dBmResistor Color Code Calculator4 band, 5 bandLED Resistor CalculatorSingle LEDVoltage Divider CalculatorOutput and resistor valuesResistors in Series and ParallelTotal resistanceOhm's Law CalculatorV, I, R and PRC Time Constant CalculatorCharge and dischargeReactance CalculatorXL and XCLC Resonant Frequency CalculatorTank circuitsCapacitors in Series and ParallelTotal capacitanceCapacitor Energy CalculatorJoules and chargeDecibel CalculatorPower and voltage ratiosADC Resolution CalculatorBits and LSB size
More Calculator Categories
Temperature Measurement15 live toolsInstrumentation Signal4 live toolsPLC Digital Signal3 live toolsFlow Measurement19 live toolsLevel Measurement12 live toolsPressure Measurement13 live toolsControl Valve12 live toolsCalibration10 live toolsSafety and SIL7 live toolsAnalytical8 live toolsElectrical37 live toolsUnit Converters76 converters, 700+ units