Why VA Math Is Not Simple Addition
One of the most confusing aspects of VA disability is how ratings are combined. If you have a 50% rating for one condition and a 30% rating for another, your combined rating is not 80%. The VA uses a "whole person" theory that calculates how much of your overall health is affected by each disability, applied to the remaining healthy portion of your body.
This system means that each additional rating has a diminishing effect on your combined percentage. The closer you get to 100%, the harder it becomes to reach it by adding conditions. Understanding this math is essential for strategic claims planning.
How Combined Ratings Work
Here is how the VA calculation works step by step. Start with your highest-rated disability. That percentage represents the portion of your whole body that is disabled. The next disability is applied only to the remaining healthy portion. For example, with a 50% and a 30%: you start at 50% disabled (50% healthy). The 30% is applied to the remaining 50%, which equals 15%. Add that to 50% and you get 65%, which rounds to 70%.
Example: A veteran with ratings of 50%, 30%, and 20% does not have a 100% combined rating. Using VA math: 50% + 30% of 50% (15%) = 65%. Then 20% of 35% (7%) = 72%. Rounded to the nearest 10, that is a 70% combined rating.
The Bilateral Factor
The bilateral factor is a special calculation that benefits veterans with disabilities affecting both sides of the body or both arms and legs. If you have conditions rated on both the left and right side, the VA first combines those ratings using standard VA math, then adds an extra 10% of the combined bilateral value before combining it with your other ratings. This small bonus can sometimes push you over a rounding threshold to the next higher rating.
Rounding Rules
After calculating your combined percentage, the VA rounds to the nearest 10%. The rounding follows standard rules: 0.5 and above rounds up, below 0.5 rounds down. This means a combined value of 65% rounds up to 70%, while 64% rounds down to 60%. That single percentage point can mean a difference of hundreds of dollars per month in compensation. This is why adding even a small secondary condition can have a significant financial impact if it pushes you past a rounding threshold.
Strategic Implications for Your Claim
- Prioritize getting your highest-rated conditions established first, as they have the greatest impact on your combined rating.
- Even a 10% secondary condition can push you past a rounding threshold and significantly increase your monthly compensation.
- If you are close to a breakpoint (like 94% trying to reach 100%), consider TDIU as an alternative path to 100% compensation.
- Use a VA combined ratings calculator to model different scenarios before deciding which conditions to claim.
Get Your Free Benefits Audit
Our AI analyzes your service history and identifies every benefit you may be missing.
Start Your Audit