Standard EIA Decade Resistor Values Table

 

The Electronic Industries Association (EIA), and other authorities, specify standard values for resistors, sometimes referred to as the "preferred value" system.  The preferred value system has its origins in the early years of the last century at a time when most resistors were carbon-graphite with relatively poor manufacturing tolerances.  The rationale is simple - select values for components based on the tolerances with which they are able to be manufactured.  Using 10% tolerance devices as an example, suppose that the first preferred value is 100 ohms.  It makes little sense to produce a 105 ohm resistor since 105 ohms falls within the 10% tolerance range of the 100 ohm resistor. The next reasonable value is 120 ohms because the 100 ohm resistor with a 10% tolerance is expected to have a value somewhere between 90 and 110 ohms. The 120 ohm resistor has a value ranging between 110 and 130 ohms. Following this logic, the preferred values for 10% tolerance resistors between 100 and 1,000 ohms would be 100, 120, 150, 180, 220, 270, 330 and so on (rounded appropriately); this is the E12 series shown in the table below.

 

The EIA "E" series specify the preferred values for various tolerances.  The number following the "E" specifies the number of logarithmic steps per decade.  The table below is normalized for the decade between 100 and 1,000.  The values in any decade can be derived by merely dividing or multiplying the table entries by powers of 10.  The series are as follows:

 

E3     50% tolerance (no longer used),
E6     20% tolerance,
E12   10% tolerance,
E24     5% tolerance,
E48     2% tolerance,
E96     1% tolerance,
E192   0.5, 0.25, 0.1% and higher tolerances.

 

 

 

E6

10

15

22

33

47

68

.

.

.

.

.

.

E12

10

12

15

18

22

27

33

39

47

56

68

82

E24

10

11

12

13

15

16

18

20

22

24

27

30

"

33

36

39

43

47

51

56

62

68

75

82

91

E48

100

105

110

115

121

127

133

140

147

154

162

169

"

178

187

196

205

215

226

237

249

261

274

287

301

"

316

332

348

365

383

402

422

442

464

487

511

536

"

562

590

619

649

681

715

750

787

825

866

909

953

E96

100

102

105

107

110

113

115

118

121

124

127

130

"

133

137

140

143

147

150

154

158

162

165

169

174

"

178

182

187

191

196

200

205

210

215

221

226

232

"

237

243

249

255

261

267

274

280

287

294

301

309

"

316

324

332

340

348

357

365

374

383

392

402

412

"

422

432

442

453

464

475

487

499

511

523

536

549

"

562

576

590

604

619

634

649

665

681

698

715

732

"

750

768

787

806

825

845

866

887

909

931

953

976