Ohmsums

SMD resistor code calculator

Type the marking on a surface-mount resistor to get its value, or type a value to get its 3-digit, 4-digit and EIA-96 codes. Results update as you type.

Indicative calculation; verify before use.

Printable EIA-96 code chart (01 to 96 with every multiplier letter), print or save as PDF

Code to value

Try:

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Code type
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Reading
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Ohms
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Tolerance
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Standard series
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Value to code

Ω

MarkingCodeMeans
3-digit
usually ±5 %		––
4-digit
±1 % or better		––
EIA-96
±1 %, 0603		––

Which of the codes a part carries depends on its size and tolerance. The smallest parts (0402 and below) usually have no marking at all.

How it works

3-digit ABC → AB × 10^C Ω 472 = 47 × 10² = 4.7 kΩ 4-digit ABCD → ABC × 10^D Ω 4702 = 470 × 10² = 47.0 kΩ R = decimal point 4R7 = 4.7 Ω, R47 = 0.47 Ω, 0R10 = 0.10 Ω EIA-96 NN L → E96 value no. NN × multiplier L 0, 000, 0000 = zero-ohm jumper

3-digit code (usually ±5 %, E24 values): the first two digits are the value and the third is the number of zeros. 103 is 10 followed by three zeros = 10 kΩ, and 220 is 22 Ω, not 220 Ω. Below 10 Ω the letter R is the decimal point: 4R7 = 4.7 Ω. A short bar under a 3-digit code marks a ±1 % part with an E24 value.

4-digit code (±1 % or better): three digits and the number of zeros, so 1002 = 100 × 10² = 10.0 kΩ and 3160 = 316 Ω. Below 100 Ω R is the decimal point again: 31R6 = 31.6 Ω, 1R00 = 1 Ω.

EIA-96 code (±1 %, used on 0603 parts that are too small for four characters): two digits and a letter. The digits 01 to 96 are the position of the value in the E96 series (01 = 100, 02 = 102, … 96 = 976), and the letter is the multiplier: Z ×0.001, Y ×0.01, X ×0.1, A ×1, B ×10, C ×100, D ×1000, E ×10 000, F ×100 000. Yageo, Bourns and TT Electronics agree on Y, X and A to F; Z is only in the Bourns table.

R, S and H are not used the same way by everyone. The TT Electronics table gives S or Y = ×0.01 and R or X = ×0.1, while most online tables give R = ×0.01 and S = ×0.1. H is ×10 in TT's table but ×10⁷ in Bourns' current CR datasheet. For these letters the calculator shows both readings; measure the part.

Zero-ohm jumpers are marked 0, 000 or 0000. They are links, not precise resistors: Bourns specifies 50 or 100 mΩ or less, depending on size. Current-sense resistors use their own marks; a long bar on a code such as 047 means the leading R is left out (R047 = 0.047 Ω).

Worked example: an 0603 resistor marked 01C. Code 01 is the first E96 value, 100, and C means × 100, so 100 × 100 = 10 000 Ω = 10.0 kΩ, ±1 %. The same 10.0 kΩ ±1 % value on an 0805 part is marked 1002 (100 × 10² Ω), and a ±5 % 10 kΩ part is marked 103 (10 × 10³ Ω).

Markings are not fully standardised across manufacturers. Check the datasheet when a part matters, and measure unknown parts.

Sources (checked 2026-11-01):