SSDI payments vary significantly from person to person because they're based on your individual work history and earnings record. Understanding how much you might receive means learning how Social Security calculates your benefit amount, what factors affect the payment, and how your age or other circumstances might change what you get each month.
The articles here explain how your work history translates into a dollar amount, what happens if you've had gaps in employment, how your benefit changes if you start receiving payments at different ages, and what other situations—like working while receiving SSDI or having dependents—affect your monthly payment.