Question: How much can I get in Social Security disability insurance benefits? I injured my back on the job and received a 50% permanent disability rating from workers’ compensation. I’m not able to work at all right now due to low back pain.

Answer: Social Security Disability Insurance (SSDI) is a part of the Social Security retirement program, and how much you get in benefits depends on the amount of your wages or salary over the past several decades (though only the wages on which you paid Social Security taxes are counted).

Unlike workers’ compensation and veterans benefits, your monthly Social Security benefit doesn’t depend on how disabled you are. To Social Security, you are either disabled (unable to earn at least $1,040 per month) or not. And because Social Security’s and workers’ comp’s definitions of disability are so different, the fact that you were approved for workers’ comp won’t help you get approved for Social Security disability.

Instead of basing your benefit on a percentage of disability, Social Security uses a complicated formula to calculate your benefits using your “average indexed monthly earnings” (AIME) and “primary insurance amount” (PIA). Your AIME is based on your highest wages of the last 35 years of your earnings, and a percentage of your AIME is used to come with your PIA, the base amount of your monthly benefit. (See Nolo’s article on the AIME and PIA calculations for more.)

Social Security can give you an estimate of your PIA and your monthly disability benefit so that you don’t need to calculate it yourself. Or, go to my Social Security to see your Social Security statement online; it will show what you would receive in SSDI if you are approved for disability benefits.

In 2013, the average SSDI benefit amount is $1,132 per month, but workers who were highly paid can receive up to up to $2,533 per month.

That said, workers’ comp monthly payments or a lump sum settlement can reduce your monthly SSDI benefit so that you aren’t paid a total of more than 80% of the income you earned before your disability. For more information, see Nolo’s article on minimizing the effect of workers’ compensation on your Social Security disability benefits.