I am self employed. What is the maximum amount I can contribute to my SEP-IRA

where can I enter the ira contribution for 2016 as a self-employed?

As a self-employed person, for 2016 you can contribute no more than the lesser of:

• 20% of your self-employment income
  
• $53,000

For this calculation, your "self-employment income" is your net profit from self-employment minus the deductible portion of your self-employment taxes.