What are standard resistor values?

You may have noticed that certain values of resistors keep cropping up and some don’t exist. That is because there are standard resistor values. The values that were chosen were all to do with tolerances and manufacturing in the early days of electronics.

If you look at the E12 standard resistor values when resistors were commonly only of a 10% tolerance, the value of 82 Ohms could be 10% higher which would add on another 8.2 Ohms so it could be as high as 90.2 Ohms. The next value up on the E12 standard resistor values is 100 Ohms so it could be 10% lower which would take off 10 Ohms so it could actually be as low as 90 Ohms so technically it could be lower than a 82 Ohm resistor which we have just seen could be as high as 90.2 Ohms!

An 82-ohm resistor at 10% tolerance could be as low as 73.8 Ohms. The next value down on the E12 scale is 68 Ohms which could be as high as 74.8 Ohms. This means that any value of resistor manufactured will fit somewhere in the range, so no manufactured resistors need to be thrown away. The values shown in the tables below are just the figures, so 27 would refer to 27 Ohms 270 ohms and 270K etc.

As manufacturing techniques have improved the number of standard resistor values has increased and the original E6 series has progressed now to the E192. With the number of values becoming more precise the resistor code had to be overhauled as it wasn’t possible to indicate a 115K resistor using the old four-band system. You can read about resistor colour codes here.

Listed below are the standard resistor values that are available.

If you need to measure the value of a resistor, have a look at my article on testing electronic components.

E6 series

10	15	22	33	47	68

E12 series

10 33	12 39	15 47	18 56	22 68	27 82

E24 series

10 18 33 56	11 20 36 62​	12 22 39 68	13 24 43 75	15 27 47 82	16 30 51 91

E48 series

100 133 178 237 316 422 562 750	105 140 187 249 332 442 590 787	110 147 196 261 348 464 619 825	115 154 205 274 365 487 649 866	121 162 215 287 383 511 681 909	127 169 226 30 402 536 715 953

E96 series

100 115 133 154 178 205 237 274 316 365 422 487 562 649 750 866	102 118 137 158 182 210 243 280 324 374 432 499 576 665 768 897	105 121 140 162 187 215 249 287 332 383 442 511 590 681 787 909	107 124 143 165 191 221 255 294 340 392 453 523 604 698 806 931	110 127 147 169 196 226 261 301 348 402 464 536 619 715 825 953	113 130 150 174 200 232 267 309 357 412 475 549 634 732 845 976​

E192 series

100 115 133 154 178 205 237 274 316 365 422 487 562 649 750 866	101 117 135 156 180 208 240 277 320 370 427 493 569 657 759 876​	102 118 137 158 182 210 243 280 324 374 432 499 576 665 768 887​	104 120 138 160 184 213 246 284 328 379 437 505 583 673 777 898	105 121 140 162 187 215 249 287 332 383 442 511 590 681 787 909	106 123 142 164 189 218 252 291 336 388 448 517 597 690 796 920	107 124 143 165 191 221 255 294 340 392 453 523 604 698 806 931	109 126 145 167 193 223 258 298 344 397 459 530 612 706 816 942	110 127 147 169 196 226 261 301 348 402 464 536 619 715 825 953	111 129 149 172 198 229 264 305 352 407 470 542 626 723 835 965	113 130 150 174 200 232 267 309 357 412 475 549 634 732 845 976​	114 132 152 176 203 234 271 312 361 417 481 556 642 741 856 988