If you don't want to set up an account with Social Security, you can still get a rough estimate of what your monthly disability benefits would be.  While this is helpful for planning purposes, you are far better off if you do set up an account with Social Security.  Such

Do The Numbers Add Up?

an account will give you access to all sort of information in addition to potential disability benefits.

In the meantime, try this calculator available from the Washington Post:

How Much Would I Get In Disability Benefits?

One clever feature of this calculator shows you how much you make now versus what Social Security would pay for disability benefits.  The contrast between the numbers can be startling. Seeing how much less Social Security disability pays might prompt some would-be applicants to stay on the job. 

Once you have looked at the numbers, let me know if they surprised you. Was it less than you expected? More? Did this influence your plans to apply for Social Security disability?