– The currency used in ST Kitts Nevis is the Eastern Caribbean Dollar better known as the EC Dollar. The exchange rate at the banks if you want to buy US is USD $1.00 = EC $2.7169. However the selling rate is US $1.00 = EC $2.67. The generally accepted exchange rate is US $1.00 = EC $2.67. However if you use your US on the street you are very likely only going to get EC $2.50 for your US dollar.