Quickly calculate your VA combined disability rating using the official “VA math” formula. Enter your individual ratings below and see a step-by-step remaining efficiency chart.
Add each service-connected condition as a whole number (0–100). The VA combines them using remaining efficiency, it doesn’t just add them.
Enter one or more ratings on the left and click “Calculate combined rating” to see your unofficial combined rating and how the VA applies each percentage.
Important: This is an unofficial educational tool and does not guarantee any VA decision. Actual payments depend on your official rating, dependents, and VA rules in effect at the time of your decision.
This calculator helps you understand how the U.S. Department of Veterans Affairs (VA) combines multiple disability ratings using the official VA math method. Instead of simply adding ratings together, the VA applies each percentage to the remaining efficient portion of your body.
Most veterans expect their disability ratings to add up normally:
Example: 50% + 50% = 100%
However, the VA does not add percentages arithmetically. Instead, the VA uses a remaining efficiency formula, where each new condition is applied only to the healthy portion of the body that remains after previous ratings.
Suppose you have two ratings:
The combined raw rating becomes 75%. The VA then rounds this to the nearest 10%, so your official combined rating becomes 80%, not 100%.
Step 1 — Sort conditions from highest to lowest
The VA always applies the largest disability percentages first, followed by smaller ones.
Step 2 — Calculate remaining efficiency
Remaining efficiency is the portion of the body that is still considered “healthy.” The formula is:
Remaining Efficiency = 100 − Current Combined Rating
Step 3 — Apply the next disability to the remaining efficiency
Each new disability is applied to the remaining efficiency, not the full 100%. For each step:
Added Amount = Remaining Efficiency × (Next Rating ÷ 100)
Step 4 — Repeat until all ratings are applied
The VA continues this process until every individual rating has been applied.
Step 5 — Round to the nearest 10%
Once all disabilities have been combined, the raw combined rating is rounded to the nearest 10%. For example:
Many veterans are surprised when their combined rating is lower than the simple sum of their percentages. This is not a mistake; it is a result of the VA’s remaining efficiency method. Because each disability applies only to what is still considered healthy, it becomes harder to reach 100% without one extremely high rating or several very high ones.
No. The VA combines disability ratings using a weighted system based on remaining efficiency. Each new rating applies only to the portion of your body that is still considered efficient. This means the combined rating will almost always be lower than the arithmetic sum of individual percentages.
Because each rating is applied to the remaining efficient portion of your body, not the full 100%. As more ratings are added, the amount of remaining efficiency gets smaller, making it progressively harder to reach 100%.
No. This is an unofficial educational tool. It reflects the VA’s published method for combining ratings, but it is not an official VA system and does not make any decisions about your claim.
This calculator focuses on determining your combined disability percentage. To find the monthly compensation amount, you must compare your final combined rating to the most recent VA disability compensation tables, which also consider eligible dependents.
This version of the calculator does not include the bilateral factor. The bilateral factor is an additional calculation applied when disabilities affect both sides of paired extremities (such as both arms or both legs). A separate bilateral factor calculator can be developed as an add-on tool.
You can use this calculator to understand how your combined rating may be computed, but it is not official evidence. The VA bases its decisions on your medical records, service records, exams, and the law in effect at the time of your claim.
Understanding how combined ratings are calculated can help you:
This VA disability combined rating calculator:
VAClaimMath.com exists to give veterans clear, practical tools that make VA math easier to understand. This site is not affiliated with the Department of Veterans Affairs and does not provide legal advice or make claim decisions. Instead, it is designed as a straightforward educational resource you can use alongside:
If you need help telling your service story or organizing evidence for a claim, you can also explore: