What is VA Math? How does VA Math work?

Welcome to Mind-Boggling VA Math. Prepare yourself. Whoever thought of this was nuts! Seriously nuts.
That being said, Don’t worry! You’ll be fine! We’ll help you through VA Math step by step with a few examples. You should now feel very reassured and ready to face VA Math head-on.

Let’s start at the beginning. What is VA Math? VA Math is the math used to combine the Military Disability Ratings of multiple conditions to give a veteran a single overall, or "combined", rating. In other words, if a person has more than one condition that is rated for Military Disability, then each of the ratings are combined (note that the key word here is “combined” not “added”) together using VA Math to give one overall rating. This single rating is then used to determine the exact type and amount of Military Disability Benefits the veteran receives.

VA Math is used for both DoD Disability and VA Disability.

So here’s how VA Math works. Each condition is a percentage of the disability of the service member. When combined together, however, each percentage is not a percentage of the entire service member but a percentage of what is left after other percentages have been subtracted. Got that? No? Well here’s an example:

Billy’s entire body is equal to 100%. Let’s say that Billy has three rated conditions. The first is a knee injury that is rated 30%. The second is a shoulder injury rated 20%. The last is a back injury rated 10%. Instinct would assume that the combined rating would be 60% (30 + 20 + 10 = 60). Unfortunately, that’s not the case with VA Math.

First start with the largest rating, 30%. This rating is then subtracted from the total body rating of 100%. Of the total body, now only 70% remains. So instead of simply subtracting 20 for the shoulder’s 20%, you can only subtract 20% of the 70 that is left, which is 14 (0.2 x 70 = 14). 70 minus 14 is 56. Now, since only 14 was subtracted from the total body, only 14 is added to the total combined rating. (Take a deep breath. Following along with the table below might help…)

Now for the last 10%. Again we can only subtract 10% of what is left of the total body. Thus, 10% of 56 is 5.6 (0.1 x 56 = 5.6). 56 minus 5.6 is 50.4. And again, since only 5.6 was subtracted from the total body, only 5.6 is added to the combined rating. So far, Billy’s rating is 30% + 14% + 5.6% = 49.6%.
Once all the conditions are counted, then the total combined rating is rounded to the nearest 10. 49.6%, therefore, equals 50% total disability.