The percentage of income tax that you will pay is generally around 16%, but it depends on the state where you will go. Some states have higher tax rates, but those states typically have higher wages. In general, you should expect to pay the following taxes:

• Federal taxes are normally 10% of the wages
• State taxes vary by state but are an average of 6% of wages (for detailed info about tax rates in various states, please see http://www.taxadmin.org/fta/rate/tax_stru.html and for the recent changes in tax declaration see https://www.irs.gov/pub/irs-pdf/p5307.pdf)
• J1 visa holders do not pay Social Security and Medicare taxes