When traveling to Sweden, it's important to remember that the electrical outlets used in this Scandinavian country are different from those used in the United States. Sweden uses the Europlug (Type C and F) for electricity, which has two round prongs and outputs 230 volts of power in Sweden.
Since the United States uses outlet Type A and B—which feature two flat pins or two flat pins and a round pin—you will be unable to use American appliances in Sweden without plugging them into an adapter and possibly a converter.
Power adapters and step-down transformers (power converters) are relatively cheap, and you can generally easily buy them while abroad in any major city. Still, it's a good idea to pack these electrical devices before the trip and confirm your appliances can accept 230 volts prior to departing. As a sidenote, Iceland also uses 230v.
USB Power Adapters
Virtually everyone who travels has a cellphone that will need daily charging, and many also take along tablets and laptop computers that will need power.
These devices power cords generally automatically adapt to whatever the voltage is, so you likely will not need a power converter to charge them in Sweden, but you will need a USB power adapter to fit into the plugs in Sweden. Just plug the USB end of your device's charger into the USB travel adapter as you normally plug it into the power brick you use at home.
If these devices are the only electrical items you are traveling with, this is the only adapter you need. (Even though these devices should automatically adapt to the higher voltage in Sweden and across Europe, it is a good idea to review the user manual about your specific device before you go.)
Power Voltage for Appliances
If attempting to use American electrical appliances in Sweden, be aware that in the United States' electrical system typically operates on 110 volts of output, while Sweden's operates at 230 volts. (Other countries in Europe operate between 220 and 240 volts).
If you attempt to plug in an American appliance that is only designed for 110 volts, it could fry the appliance completely. It could also start an electrical fire, so definitely be aware of which voltage your appliance can handle.
To prevent any issues, check the label near the appliance's power cord that shows its voltage rating, which is typically 100 to 240 volts or 50 to 60 Hertz. If your appliance is not rated for up to 240 volts or 50 to 60 Hertz, you'll need to buy a power converter, which will reduce the voltage to just 110 for your appliance.
These converters cost a little more than simple adapters. If you need to use a power converter to limit the voltage flowing from a Swedish outlet, you can easily plug this device into a universal converter or one that converts from Type A and B to Type C and F.
As a general rule, it's a bad idea to bring any type of hairdryer to Sweden because it's difficult to find a suitable converter because of their high power consumption. Instead, you can check if your accommodation in Sweden has one in the room or if not, just buy a cheap one locally.
Buying the Right Power Adapter
When it comes to buying a power adapter for international travel, especially when visiting more than one country on a trip, getting a universal adapter is really the way to go—but you'll still need to make sure you don't also need to get a converter depending on your appliance's voltage capacity.
Sweden's Type C outlets feature two round holes for the plug and don't have a ground, while Type F outlets have these same two round holes with a third ground pin.
American outlets operate in essentially the same way except for that Type A outlets have two thin rectangular holes, and Type B outlets have an additional third round hole for the ground. Universal outlets allow you to convert Type A and B to Type C and F easily.