SMD resistor codes.

Type what's printed on the chip (472, 4702, 01C, 4R7) and get the resistance. Or find the codes for a value.

INPUT · PRINTED CODE AUTO-DETECT

// Code on the resistor

Try one

3 digits: two significant digits and a power of ten (5% parts). 4 digits: three digits and a power of ten (1%). Two digits and a letter: EIA-96 (1%). R is the decimal point. AUTO picks the scheme from the pattern; the buttons above force one.

// DECODED · RESISTANCE ↻ LIVE

NOMINAL VALUE

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SCHEME

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IN OHMS

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$ —
→ —

// Cheat sheet

Three marking schemes, one chip

3-digit · 5% parts

Two digits, then the number of zeros. 472 = 47 and two zeros = 4,700 Ω. 000 is a zero-ohm jumper.

4-digit · 1% parts

Three digits, then the number of zeros. 4702 = 470 and two zeros = 47,000 Ω. 1001 = 1 kΩ.

EIA-96 · small 1% parts

Two digits pick a value from the table below, a letter multiplies it. 01C = 100 × 100 = 10 kΩ.

// EIA-96 CODES · 01–96 → E96 BASE VALUE REFERENCE

CODE	VALUE	CODE	VALUE	CODE	VALUE	CODE	VALUE
01	100	25	178	49	316	73	562
02	102	26	182	50	324	74	576
03	105	27	187	51	332	75	590
04	107	28	191	52	340	76	604
05	110	29	196	53	348	77	619
06	113	30	200	54	357	78	634
07	115	31	205	55	365	79	649
08	118	32	210	56	374	80	665
09	121	33	215	57	383	81	681
10	124	34	221	58	392	82	698
11	127	35	226	59	402	83	715
12	130	36	232	60	412	84	732
13	133	37	237	61	422	85	750
14	137	38	243	62	432	86	768
15	140	39	249	63	442	87	787
16	143	40	255	64	453	88	806
17	147	41	261	65	464	89	825
18	150	42	267	66	475	90	845
19	154	43	274	67	487	91	866
20	158	44	280	68	499	92	887
21	162	45	287	69	511	93	909
22	165	46	294	70	523	94	931
23	169	47	301	71	536	95	953
24	174	48	309	72	549	96	976

// EIA-96 MULTIPLIER LETTERS THIRD CHARACTER

LETTER	MULTIPLIER	EXAMPLE
Z	×0.001	01Z = 0.1 Ω
Y / R	×0.01	01Y = 1 Ω
X / S	×0.1	68X = 49.9 Ω
A	×1	01A = 100 Ω
B / H	×10	22B = 1.65 kΩ
C	×100	01C = 10 kΩ
D	×1,000	01D = 100 kΩ
E	×10,000	01E = 1 MΩ
F	×100,000	01F = 10 MΩ

// Worked examples

Reading the three schemes

Surface-mount resistors are too small for color bands, so they carry a printed code in one of three schemes. 3-digit codes are two significant digits and a power of ten, which is enough for 5% parts from the E24 series. 4-digit codes add a third significant digit for 1% parts. EIA-96 exists because 1% parts need three significant digits but an 0603 chip only has room for three characters in total: the E96 series has exactly 96 values per decade, so a two-digit index (01 to 96) plus a multiplier letter fits.

3-digit. 472 is 4, 7 and two zeros: 47 × 10² = 4,700 Ω = 4.7 kΩ. 4-digit. 4702 is 4, 7, 0 and two zeros: 470 × 10² = 47,000 Ω = 47 kΩ. EIA-96. 22B: code 22 in the table is 165, and B is ×10, so 165 × 10 = 1,650 Ω = 1.65 kΩ. 68X is 499 × 0.1 = 49.9 Ω.

Gotcha: watch where the R is. R is the decimal point, so R47 = 0.47 Ω, 4R7 = 4.7 Ω and 4R70 is 4.70 Ω on a 1% part. A 0 or 000 isn't a missing value, it's a zero-ohm jumper: a link that lets the board route a trace over another. EIA-96 uses R as an alternate for Y (×0.01), so 47R is ambiguous; AUTO reads it as EIA-96 (3.01 Ω) and the 3-DIGIT button reads it as 47 Ω.

Treat the code as a hint. 0402 and smaller parts are usually unmarked, and a code can be misread upside down (601 vs 109). If it matters, measure the part out of circuit with a multimeter.

// Common questions

Questions people actually ask

What does 472 mean on an SMD resistor?

It is a 3-digit code: 47 followed by two zeros, so 4,700 Ω, which is 4.7 kΩ. The last digit is always the number of zeros to add.

What does 01C mean on an SMD resistor?

It is an EIA-96 code for a 1% part. Code 01 is the E96 base value 100 and the letter C multiplies by 100, so 01C is 10,000 Ω, or 10 kΩ.

What does R10 or 4R7 mean on a resistor?

The R is the decimal point. R10 is 0.10 Ω and 4R7 is 4.7 Ω. Low values like these are common for current-sense resistors.

What is the difference between 3-digit and 4-digit SMD codes?

A 3-digit code has two significant digits and a multiplier and is used on 5% parts; a 4-digit code has three significant digits and a multiplier for 1% parts. Both give 1 kΩ as 102 and 1001 respectively, but only the 4-digit code can say 1.02 kΩ (1021).

How do I read an SMD resistor marked 0?

A resistor marked 0, 00 or 000 is a zero-ohm jumper. It is a link in a resistor package, used to bridge a gap on the board or as a configuration option, and its resistance is only a few tens of milliohms.

Why does my tiny resistor have no marking?

0402 and smaller chips are too small to print on, so they are usually left blank, and some 0603 parts are unmarked too. Measure the part out of circuit with a multimeter, or check the reel label or the board's bill of materials.

CODE	VALUE	CODE	VALUE	CODE	VALUE	CODE	VALUE
01	100	25	178	49	316	73	562
02	102	26	182	50	324	74	576
03	105	27	187	51	332	75	590
04	107	28	191	52	340	76	604
05	110	29	196	53	348	77	619
06	113	30	200	54	357	78	634
07	115	31	205	55	365	79	649
08	118	32	210	56	374	80	665
09	121	33	215	57	383	81	681
10	124	34	221	58	392	82	698
11	127	35	226	59	402	83	715
12	130	36	232	60	412	84	732
13	133	37	237	61	422	85	750
14	137	38	243	62	432	86	768
15	140	39	249	63	442	87	787
16	143	40	255	64	453	88	806
17	147	41	261	65	464	89	825
18	150	42	267	66	475	90	845
19	154	43	274	67	487	91	866
20	158	44	280	68	499	92	887
21	162	45	287	69	511	93	909
22	165	46	294	70	523	94	931
23	169	47	301	71	536	95	953
24	174	48	309	72	549	96	976

CODE	VALUE	CODE	VALUE	CODE	VALUE	CODE	VALUE
01	100	25	178	49	316	73	562
02	102	26	182	50	324	74	576
03	105	27	187	51	332	75	590
04	107	28	191	52	340	76	604
05	110	29	196	53	348	77	619
06	113	30	200	54	357	78	634
07	115	31	205	55	365	79	649
08	118	32	210	56	374	80	665
09	121	33	215	57	383	81	681
10	124	34	221	58	392	82	698
11	127	35	226	59	402	83	715
12	130	36	232	60	412	84	732
13	133	37	237	61	422	85	750
14	137	38	243	62	432	86	768
15	140	39	249	63	442	87	787
16	143	40	255	64	453	88	806
17	147	41	261	65	464	89	825
18	150	42	267	66	475	90	845
19	154	43	274	67	487	91	866
20	158	44	280	68	499	92	887
21	162	45	287	69	511	93	909
22	165	46	294	70	523	94	931
23	169	47	301	71	536	95	953
24	174	48	309	72	549	96	976

CODE	VALUE	CODE	VALUE	CODE	VALUE	CODE	VALUE
01	100	25	178	49	316	73	562
02	102	26	182	50	324	74	576
03	105	27	187	51	332	75	590
04	107	28	191	52	340	76	604
05	110	29	196	53	348	77	619
06	113	30	200	54	357	78	634
07	115	31	205	55	365	79	649
08	118	32	210	56	374	80	665
09	121	33	215	57	383	81	681
10	124	34	221	58	392	82	698
11	127	35	226	59	402	83	715
12	130	36	232	60	412	84	732
13	133	37	237	61	422	85	750
14	137	38	243	62	432	86	768
15	140	39	249	63	442	87	787
16	143	40	255	64	453	88	806
17	147	41	261	65	464	89	825
18	150	42	267	66	475	90	845
19	154	43	274	67	487	91	866
20	158	44	280	68	499	92	887
21	162	45	287	69	511	93	909
22	165	46	294	70	523	94	931
23	169	47	301	71	536	95	953
24	174	48	309	72	549	96	976