How Do You Dial Croatia From The United States?

Phone Card Call Croatia from area code 301
eCallChina has very good phone cards with cheap rates  for calling Croatia from area code 301, you could also go on line to their site www.ecallchina.com to find out your area code and the rate you will be charged
A Local access number has less operational costs than a toll free number, so usually calling from local access numbers will be  cheaper  than from a toll free number.  This site can provide you with the  local access numbers in 301 area code to call Croatia. Use  local phone cards to call Croatia and save some money.
If you cannot find local access numbers in 301 area code?
If you have cellular phone plan with unlimited free domestic long distance in weekend and night, then you can take advantage of it to call any local access numbers in other states to get more minutes.
Otherwise, you can check the best rate to call Croatia from toll free numbers.
To avoid running up unwanted toll or long distance charges when calling local access numbers, be sure to check the "local" access number you are using. It is always up to the consumer to verify that the number they are dialling is a local call.
Those who do not check the number before calling run the risk of incurring unexpected phone charges.

Check out Time Dial. International Dialing Codes and Area Codes With Instructions

Croatia International Dialing Codes, Area Codes

Heres a link for the international phone card price comparison search engine Croatia Phone Cards Cpmparison. Might come in handy

You have to dial 011+Country code+the phone number.....the country code for Croatia is 385