SMD Resistor Code Calculator

Type the marking printed on a surface-mount resistor to get its value. Handles 3-digit, 4-digit, R-notation and EIA-96 codes.

This marking can be read more than one way. A trailing R is the decimal point on ordinary parts but a ×0.01 multiplier on 1% EIA-96 parts. Measure the resistor with a multimeter, or check the size of the part (EIA-96 codes are used on 1% parts).

Tolerances shown are the usual ones for this marking system; the code itself does not state the tolerance.

Find the SMD code for a value

EIA-96 code table

How SMD resistor codes work

Surface-mount (SMD) resistors are too small for colour bands, so their value is printed as a short code. Very small parts, such as the 0402 size and smaller, often have no marking at all and must be measured. There are four common systems.

3-digit code

Used on standard parts, usually ±5%. The first two digits are the significant figures and the third digit is the number of zeros. For example, 472 is 47 followed by two zeros, which is 4,700 Ω or 4.7 kΩ. A code of 100 is 10 Ω, not 100 Ω.

4-digit code

Used on precision parts, usually ±1%. The first three digits are the significant figures and the fourth is the number of zeros. For example, 1002 is 100 followed by two zeros, which is 10,000 Ω or 10 kΩ, and 4751 is 4,750 Ω.

R notation for small values

Values below 10 Ω cannot be written with the digit codes, so the letter R is used as the decimal point. 4R7 is 4.7 Ω, R10 is 0.1 Ω and 0R22 is 0.22 Ω. Current-sense resistors often use this marking.

EIA-96 code

Small 1% resistors use a three-character code: two digits and a letter. The digits are a position in the E96 list of preferred values (01 = 100, 02 = 102 and so on up to 96 = 976), and the letter is the multiplier. For example, 68X is 499 × 0.1 = 49.9 Ω and 01C is 100 × 100 = 10 kΩ. Use the table above to look up any code.

Frequently Asked Questions

Reading through-hole parts instead? Use the Resistor Colour Code Calculator or the Capacitor Code Calculator.