Wherever I go in the world, the electrical outlets I plug my shaver in to seem to be the same. However, depending on where I am the regular power outlets will be different: some have three pins, some have two; some have an earth pin, some don't; some have flat pins, some have round pins, some have square pins.

I'm not sure if this is right place to ask this, but I can't find anywhere better (please let me know if I should move my question!): how is it that the electrical industry got its act together sufficiently to standardise shaver outlets, but not regular power outlets?

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    Can you explain what you mean by "shaver outlet" ? Stateside, there is no such thing. You got your 120VAC standard and yr 204V 3phase standard, and that's about it. Are you talking about some sort of luxury hotel bathroom thingy? Sep 7, 2016 at 12:48
  • Sure! It's this sort of thing: screwfix.com/p/lap-dual-voltage-shaver-socket-115-230v-white/…
    – Jim
    Sep 7, 2016 at 12:50
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    Google can answer amazing questions, took me about 1 minute to find this very informative article that exactly answers your question.
    – Tyson
    Sep 7, 2016 at 14:13

2 Answers 2


That's not the half of it. Go in any post-1940 sleeper car at a railway museum. There's a shaver outlet and guess what. Mind you, there are only two power sources in the car, a 32v battery charged by wheel driven generators... And service steam. I'm not sure if they tap the generator to get something vaguely resembling 110VAC at random frequencies, but this passenger-car power was exceedingly filthy and only good enough to run a shaver, and the receptacle is placarded "shaver only".

Amtrak's new cars retained this placard needlessly, when they standardized train power at 480V delta served from a generator car or inverter on the locomotive.

At the time this became the norm on rail, trains were THE way to travel. I'm sure passenger liners had similar receptacles, and this spread all over the world.

"110V-ish good enough for a small brush driven DC style shunt motor" is not a particularly high standard to hit. Frequency is not an issue, and a simple transformer will do the job.

Frankly given the ubiquity of digital switching power supplies, I'd expect a new world receptacle standard which promises only some random voltage between 74 and 277 at some fixed number of watts.

As for sub-10-watt receptacles, there's already a standard for that. USB.


Well, in that case the answer is obvious: that gadget does the voltage conversion for you, similar to a laptop charging "wart on a wire" box. There's a document defining the standard somewhere for shavers the same way there's a standard, microUSB, for cellphones.

Different countries run on different voltages and frequencies (50 vs 60 Hz). [Different countries also have different coinage, languages, and toilet seat designs. Good luck with universal standardization on anything :-) ]
Different prong sets exist largely for back-compatibility; a lot of modern outlets are set up so both US and Euro plugs will fit in. Similarly, more and more gadges auto-adjust to the incoming voltage automatically.

  • Ah, not quite what I meant! It seems that whichever hotel I go into, anywhere in the world, I don't need an adaptor to charge my electric shaver. But I always need an adaptor in order to charge my laptop. That adaptor doesn't change the voltage, it just changes the shape of the connector.
    – Jim
    Sep 7, 2016 at 12:58
  • So, how come shaver sockets are standardised, but regular sockets are different depending on where I am in the world?
    – Jim
    Sep 7, 2016 at 12:59
  • @Jim Probably because someone somewhere managed to get all shaver manufacturers to use a standard interface (which sure wasn't the case in, say the 1970s), and then managed to convince hotels that their guests will be happy to have that standard converter outlet available :-). Disclaimer: I only use static razors, so never even looked for such an outlet. Sep 7, 2016 at 13:30

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