Electrical outlets in Denmark use a two-prong plug typical for continental Europe; however, Denmark strays from the Scandinavian norm, so make sure the adapter you buy is suitable for the deeper outlets in this country. When purchasing an international adapter, you'll want to look for plug types E or K as they have the correct size of two round prongs.
It's not too hard to find out what kind of plug or converter you need for electrical outlets in Denmark. Most laptops will automatically work with 220 to 230 volts, but you should check the back of your laptop for power input markings. That means you'll only need an adapter to change the shape of your power plug to fit into an outlet in Denmark, and these power adapters are relatively cheap.
However, it's also important to note that some appliances will not work or will short out if attached to a European outlet without a converter. Make sure to read up on your devices' power capacity and purchase the right type of adapter for the job.
Buying the Right Power Adaptor
Because Denmark uses type E and type K plugs, you'll need to find a power adaptor that converts your Type A or B power cord to fit in these unique sockets.
Type E sockets are French in origin and feature two round apertures and a round earth pin to ensure that the earth is engaged before the live pin contact is made while type K is uniquely Danish and features a hole for the earthing pin (which is located on Danish plugs, not sockets) in addition to the two round apertures for the plug's prongs.
When it comes to buying an adapter, you'll need to look for plug C and plug F (if it has an additional pinhole) for type E sockets and plug types C, E, and F for type K sockets. Still, be sure to check your appliance or electrical device before plugging in to make sure that you don't need to purchase an additional converter to reduce the voltage coming from the socket.
Overpowered: Purchasing Step-Down Transformers
If you bring small appliances, be careful as the shape adapter may not be enough to make these electronic devices work. While most personal electronics in recent years will accept both voltages, some older, smaller appliances don't work with the hefty 220v in Europe.
Check if the label near the appliance's power cord shows 100 to 240v and 50 to 60 Hz. If it does not, you will need a "step-down transformer," which is also called a converter. These converters will reduce the 220 volts from the outlet to provide 110 volts for the appliance, although these cost a little more than simple shape adapters.
As a word of caution, you shouldn't try to bring any type of hair dryer to Denmark as they are awfully hard to match up with a suitable converter due to astronomical power consumption. Instead, you should check if your accommodation in Denmark has one in the room, or just buy a cheap one locally.