A VAT is essentially a national sales tax that is assessed at each stage of production, with the bill passed along to consumers at the cash register. In Europe the average rate is a little under 20%. (See the nearby chart.) In the U.S., a federal VAT would presumably be levied on top of state and local sales taxes that range as high as 10%. Some nations also exempt food, medicine and certain other goods from the tax.
VATs were sold in Europe as a way to tax consumption, which in principle does less economic harm than taxing income, savings or investment. This sounds good, but in practice the VAT has rarely replaced the income tax, or even resulted in a lower income-tax rate. The top individual income tax rate remains very high in Europe despite the VAT, with an average on the continent of about 46%.
Add your local, state, gas, Medicare, and Social Security and national healthcare taxes. Kiss your money good-bye.