How VA Disability Ratings Combine: The Whole-Person Formula
VA disability ratings combine under the whole-person formula: sort ratings from highest to lowest, apply each one to the health you have left, then round the final result once to the nearest 10 percent, with 5s rounding up. Three worked examples show exactly how 50+30+20 becomes 70%, 60+40+20 becomes 80%, and 70+50 becomes 90%.
If you carry more than one service-connected condition, your ratings do not add up the way ordinary percentages do. A veteran with a 50% rating and a 30% rating does not have an 80% combined rating. This surprises almost everyone the first time they see a VA decision letter, so it helps to learn the exact rule the VA applies, because it is written into federal regulation and it decides your monthly pay.
Why the VA uses whole-person theory
The rule comes from 38 CFR 4.25, the section of the Code of Federal Regulations that defines the VA Combined Ratings Table. The thinking behind it is called the whole-person theory: a person cannot be more than 100 percent able-bodied. A first disability of 50% is treated as taking half of your full capacity. The second disability cannot take another slice of the full person, because half of that person is already accounted for. It can only affect what remains.
That single idea explains every quirk of VA math. Each new rating buys you less than the last one did, because the pool of remaining health keeps shrinking. A new 20% rating adds 20 full points to a person with no other ratings, but adds only 10 points to a veteran who is already 50% combined, and just 2 points to a veteran already at 90% combined. This is also why reaching 100% through stacking smaller ratings is mathematically difficult.
The exact formula
The VA combines disabilities in descending order of severity, starting with the most disabling condition and working down. The arithmetic equivalent, which the VA Combined Ratings Table produces for every pair, is:
Combined = 1 - ((1 - r1) x (1 - r2) x (1 - r3) ...)
where each rating is written as a decimal (50% becomes 0.50). Multiply the result by 100 to get the combined value as a percentage. Then apply the rounding rule once, at the very end: convert the combined value to the nearest degree divisible by 10, and adjust final 5s upward. So 65% becomes 70%, 64% becomes 60%, and 75% becomes 80%.
For three or more ratings, the VA combines the first two, carries that exact unrounded value forward, and combines it with the third, repeating for each additional rating. The conversion to the nearest 10% happens once per rating decision, as the last step. If you round in the middle of the chain, you can land a full bracket off, so keep the decimals until the end.
Worked example 1: 50% + 30% + 20% = 70%
This is the most common first example, because it shows both the combination and the rounding. Sort the ratings: 50, 30, 20.
Start with 100% health. The 50% rating takes half: 50 points. You have 50% health remaining. The 30% rating applies to that 50%, giving 30% of 50 = 15 points. The running total is 65%, with 35% health remaining. The 20% rating applies to the 35% remaining, giving 20% of 35 = 7 points. The final combined value is 72%.
Round once: 72% rounds to the nearest 10%, which is 70%. The veteran is paid at the 70% rate. In 2026 that means $1,808.45 per month for a veteran alone, before any dependent additions.
Worked example 2: 60% + 40% + 20% = 80%
Sort: 60, 40, 20. The 60% rating leaves 40% health remaining. The 40% rating applies to that 40%, giving 16 points, so the running total is 76% with 24% health remaining. The 20% rating applies to the 24% remaining, giving 4.8 points. The final combined value is 80.8%. (You can cross-check with the formula: 1 - (0.40 x 0.60 x 0.80) = 1 - 0.192 = 0.808, or 80.8%.)
Round once: 80.8% rounds to 80%. Notice how close this veteran is to the 90% bracket: one more 10% rating would add 10% of the remaining 19.2%, which is 1.92 points, for a combined 82.72%, still 80% after rounding. That gap between 80.8 and 85 is exactly where many veterans sit, and understanding it shows why a new rating does not always move the pay bracket.
Worked example 3: 70% + 50% = 90%
Sort: 70, 50. The 70% rating leaves 30% health remaining. The 50% rating applies to that 30%, giving 15 points. Combined value: 85%. Round once: 85% ends in 5, and the regulation adjusts final 5s upward, so this becomes 90%.
This example matters because the 5-rounds-up rule is the difference between brackets. If the second rating had been 40% instead of 50%, the math would give 70 plus 40% of 30 (12 points) = 82%, which rounds to 80%. A single 10-point difference in one rating changes the final combined rating by a full bracket.
Common questions the math raises
People often ask whether the order matters. The VA arranges disabilities in the exact order of severity and combines the first two first, and the table method matches the formula above no matter how you order the same set, because multiplication does not depend on order. Still, always list your ratings highest to lowest when doing the math by hand, since that matches the official procedure and makes the steps easy to check.
Another frequent question is the bilateral factor under 38 CFR 4.26: when disabilities affect both sides of the body, such as both knees or both arms, the VA combines those paired conditions first, adds 10% of that combined value on top (not combined, added), and then proceeds with the rest of the chain. Our calculator keeps things simple and does not apply the bilateral factor, so veterans with paired conditions may be underestimating their combined rating slightly. Mention it to your VSO or accredited representative when you file.
Finally, remember that the combined rating decides the row of the pay chart, and the pay chart decides the check. Run your own numbers with our VA disability calculator, then confirm the official figure on your VA decision letter, because the VA table value is what counts.
Figures current as of October 2026 - Source: U.S. Department of Veterans Affairs (va.gov), 2026 rates effective December 1, 2025.