When Can You Use a Travel Adapter?

April 21st, 2022
power, travel
We're currently in the UK, where outlets look like:

Since we're from the US, none of the gear we have will plug into these sockets. What if we use a travel adapter?


plug intentionally partially inserted to show pins

This accepts the pins from a US plug, and connects them directly to pins shaped for a UK socket. Is this enough? Sometimes yes, sometimes no.

The big difference between residential power in the UK and the US is that the UK uses 230V while the US uses 120V. If a device that expects 120V gets 230V it might get fried; the other way around is less likely to destroy the device but still won't work. Luckily, devices say what voltages they accept. Either they'll be labeled for a single voltage, or a range. Some examples, with whether they'll work in the UK:


110-120V: no


100-240V: yes


100-240V: yes


100-240V: yes


120V: no


100-240V: yes

A good heuristic is that most external power supplies/chargers (for laptops, phones, tablets, ...) will take a wide range of voltages while most other things (nightlights, blenders, TVs, fans, ...) will be either 120V or 230V. But best to check your specific device!

In bathrooms you may find one other type of outlet:

These exist because you'd risk electrocution with a regular outlet in a wet area like a bathroom. In the US we'd use a GFCI, but in the UK they use isolation transformers. Because it's a transformer, it's cheap to add a center tap and get half the input voltage (115V). They generally do not produce much power: UK ones are only rated for 200mA (4.6W) and if you draw much more than that you'll trip a built-in fuse. If you do have a small US device and no adapter, don't mind connecting it in a bathroom, and the device says it draws less than 200mA/4.6W and doesn't have strong frequency preferences (it will be 50Hz instead of 60Hz) you could probably use it for something other than a shaver.

Comment via: facebook, lesswrong, substack

Recent posts on blogs I like:

Ozy and Vasili Review Lilo and Stitch

Sometimes my seven-year-old, Vasili, wants to see some godawful movie that makes me want to melt my eyeballs out of my head.

via Thing of Things June 27, 2025

Elixir's Last Dance

On May 18th, the contra dance band Elixir had their last gig ever. The dance was packed: there were three hundred people. It was the only dance BIDA has ever done where they sold tickets. People flew from across the country just to hear Elixir play one la…

via Lily Wise's Blog Posts June 5, 2025

Workshop House case study

Lauren Hoffman interviewed me about Workshop House and wrote this post about a community I’m working on building in DC.

via Home April 30, 2025

more     (via openring)