The U.S. Department of Veterans Affairs (VA) does a few frustrating things as part of the VA claims process for veterans affected by service-related disabilities, such as mesothelioma, lung cancer or other diseases linked to military service.

One of these annoying things is requiring Veterans Service Representatives and VA claims agents like myself to often translate the complexities of what the VA is saying. An example of this is the way the VA combines disability ratings for claims.

I call this “VA math” because it’s different from normal math. At the VA 50% plus 50% does not equal 100%. Confused? You’re right to be. Any normal person would be.

Let’s dive into why VA math is different from the math you learned in school and the math you use at the grocery store or anywhere else in the world.

VA math is also going to impact your VA mesothelioma claim and benefits.


Combining Two VA Disability Ratings for VA Claims

According to the VA, any disability rated under 100% leaves you with some “ability” left over. If you have a 40% rating, then you still have 60% ability left over. I can literally feel you rolling your eyes about this point, but hold on, there’s lots more eye rolling-worthy content coming.

Fortunately for veterans with mesothelioma or asbestos-caused lung cancer, they almost always receive a 100% disability rating. Any asbestos cancer linked to military service is awarded  a 100% disability rating (except for a few rare exceptions).

Many veterans I talk to and help aren’t just suffering from asbestos diseases. You might not have a cancer linked to asbestos, and I want to help you understand some of the finicky elements of the VA claims system. So here are some examples of how combined VA disability ratings don’t make a lot of sense at first glance.

Now, using my previous example where you’re awarded a 40% rating, let’s say you get approved for another disability rated at 30%. The VA doesn’t just add that to your existing 40% rating to come up with 70%. No sir, that would be way too easy to understand.

Instead, the VA applies your new 30% rating to your remaining 60% ability, which is 18%, which they add to your existing 40%. Confused again? Here’s the formula, using the example above, to make it simpler to understand:

  • Start with your 40% rating.
  • Then take your new 30% rating applied to your remaining ability of 60%, which is 18%.
  • The VA adds 18% to your current 40% rating to get 58%.
  • The VA always rounds up or down to the nearest 10%, which means your new combined rating would be 60%.

Stand by for more eye rolling. Let’s say that instead of a 30% rating for your new disability, the VA assigned you a 40% rating.  Now you have two 40% ratings. Let’s do the math again:

  • 40% of your 60% remaining ability is 24%.
  • Your original rating of 40% plus 24% equals 64%.
  • That rounds down to 60%.  

Therefore, if you have an existing 40% rating, it doesn’t matter whether your new disability is rated at 30% or 40%. You still end up with a 60% rating in the end. Crazy right? It’s not uncommon. In fact, many veterans deal with this  nonsensical VA math when trying to get VA benefits for their service-related diseases.

Many of them will file an appeal, thinking the VA has added up their disability ratings improperly. Of course, those appeals are summarily denied and they just serve to clog up the already-strained VA benefits system.


Combining Three or More VA Disability Ratings for VA Claims

What this creates is a law of diminishing returns when you start adding together several disabilities rated less than 100% each. This makes it hard to get a 100% combined rating for your VA Disability Compensation claim. Let me show you why.

Let’s say you have three disability ratings rated at 60%, 50% and 20%. In normal, sensible math, this equals 130%. Surely this will get you to 100% even with VA math, right?

Wrong. Follow me on this:

  • You start with your highest rating, in this case 60%. That leaves you with 40% remaining ability.
  • Now you apply the next highest rating to that remaining 40% of ability. In this case, that is 50%, which equals 20%.
  • Add that to your 60% and you are now at 80%. We’re getting close.
  • That leaves you with a remaining ability of 20%. Now we apply your last rating of 20% to that 20%. This equals 4%.
  • Add that to your 80% and you are at 84%, which still rounds down to 80%.

A 60% rating plus a 40% rating plus a 20% rating equals an 80% combined rating. Keep getting additional disabilities rated 10% or 20% each, and you might eventually get to 100%, but it would take a lot of them. Like, a whole lot.

If you have multiple disabilities rated at less than 100% and you would like to know if the VA has assigned you the appropriate combined rating, feel free to send me your individual ratings. I’ll be happy to calculate what your combined rating should be.

You can reach me by phone at 844-838-6376 or email at


Frequently Asked Questions About VA Math for Disability Ratings

  • What is 40 VA disability?

    40 VA disability refers to the percentage rating given by the Department of Veterans Affairs (VA) to a veteran who is determined to have a service-connected disability that warrants compensation. This rating is based on the severity of the disability and the impact it has on the veteran's ability to work and perform daily activities. A 40% rating means the veteran's disability is moderately severe and may entitle them to a certain level of compensation and medical treatment.
  • How is VA disability percentage calculated?

    The VA disability percentage is calculated based on the severity and impact of a veteran's service-connected disability. The VA assigns a disability rating from 0% to 100%, in increments of 10%, based on the level of impairment caused by the veteran's condition. The VA considers factors such as the veteran's medical records, symptoms, and functional limitations in determining the disability rating. The higher the rating, the greater the amount of compensation the veteran will receive.
  • How do VA disability ratings add up?

    VA disability ratings are determined based on the severity of a veteran's service-connected disability or disabilities. Each disability is assigned a rating from 0 to 100 percent, in increments of 10 percent, based on the degree of impairment it causes in daily life. The VA then uses a combined rating table to calculate the total disability rating, which takes into account the effect of multiple disabilities on the veteran's overall functioning. The combined rating table uses a complex formula that takes into account the degree of impairment caused by each disability, but generally, the more severe the disabilities, the higher the overall rating.
  • How to calculate VA disability rating?

    The VA disability rating is calculated based on your level of disability and how it impacts your ability to work and perform daily activities. The VA will consider factors such as the severity of your mesothelioma symptoms, frequency of hospitalizations, and whether you require assistance with daily living. The VA rating system ranges from 0 to 100%, and your rating will determine the amount of compensation you are eligible to receive.

    Sources & Author

Picture of Retired LCDR Carl Jewett, VA Claims Agent

About the Writer, Retired LCDR Carl Jewett, VA Claims Agent

LCDR Carl Jewett is a retired Naval Officer who serves as the Veterans Department Director and Patient Services Director at Mesothelioma Guide. He is a VA-Accredited Claims Agent with more than 14 years of experience filing asbestos-related VA claims. He has helped over 1400 veterans who have been diagnosed with asbestos-related illnesses get approved for VA Disability Compensation, VA Pension, and/or Aid & Attendance benefits. Because veteran’s are also entitled to compensation through the legal system, Carl has communicated with many mesothelioma law firms across the country. He has gained extensive knowledge of asbestos trust funds, mesothelioma lawsuits, settlements, and the claims process. He provides both veterans and civilians with information regarding their legal options.