HOW TO – How to read a resistor (PDF)

HOW TO – How to read a resistor (PDF)

R. Stern writes –

“I work in a computer lab with a physical computing studio, and recently I cleaned out the component closet. It occurred to me that the reason we had a build up of unlabled resistors was because noone knew how to read them without the Resistulator widget or a resistance calculator website, so I made a sign to tack into the cabinet itself for offline calculation. You can download the PDF for your own use. “Link.


  • HOW TO – Read color coded resistors – Link.
  • Read resistors with Resistulator – Link.

22 thoughts on “HOW TO – How to read a resistor (PDF)

  1. RannFox says:

    I hope I don’t get in trouble for this but as I am a R&D electronic tech and having got my education from Uncle Sugar here is a little ditty that might help,

    Bad Boys Raped Our Young Girls But Violet Gave Willingly, Get Some Now

    As you can tell with a little thought that is the resister color code including the tolerence bands. If I get enough positive feedback I’ll make a pretty picture of it and post it for ya

  2. PLC.Doctor says:

    There is a typo in the example.
    It should be:
    Resistor value = 20 x 1000 = 20K ohms

  3. RobTheEngineer says:

    This is what I did – I labeled each resistor bin/drawer with the color code. I have done this for several places that I’ve consulted.

    This is an example: USBmicro resistor labels from USBmicro

    The small drawer labels are available from that site as color pdf files.

  4. wiljefv says:

    I’m new to this but his little chart on the pdf says brown is 1 and not 0. Wouldn’t that make his example on the pdf, red brown, be 21 and not 20?

  5. bekathwia says:

    Hey all, thanks for checking my work. I fixed both typos, and updated the files on my site. D’oh!
    -R. Stern

  6. RussNelson says:

    “Unlabelled resistors”? You mean somebody scraped the stripes off?

    With a little bit of practice, you don’t need to interpret the resistor color code. You just look at it and say “Oh, that’s a 6.8K resistor”. In fact, I couldn’t tell you what the colors for that would be, but I know one when I see one.

  7. philliptorrone says:

    RannFox – you won’t get in trouble and i’m not going to delete your comment – but here’s something to think about… all these new people learning electronics could learn something better than this offensive mnemonic – i realize it’s still said and taught all the time, but we don’t need to continue this. if you look at the history of this mnemonic it’s been pretty awful.

  8. bhelverson says:

    Rannfox, I learned that one from an old Navy electronics guy. And I stll use it today. I did hear one that did not involve sex, but who can remember something like that?

  9. philliptorrone says:

    again – why don’t we use this opportunity to kill a bad mnemonic.

  10. Julolidine says:

    In the multiplier column, black’s value should be 1 and not zero. I think it also makes it a bit clearer if you were to label the multipliers via factors of 10.

  11. Augustine says:

    I, appreciate the assistance coming from this site. Pls, you people should continue with it and even more.

Comments are closed.

Discuss this article with the rest of the community on our Discord server!

current: @adafruit - previous: MAKE, popular science, hackaday, engadget, fallon, braincraft ... howtoons, 2600...

View more articles by Phillip Torrone


Maker Faire Bay Area 2023 - Mare Island, CA

Escape to an island of imagination + innovation as Maker Faire Bay Area returns for its 15th iteration!

Buy Tickets today! SAVE 15% and lock-in your preferred date(s).