Ratings combine. They do not add

This is the single most common surprise in the whole system. You have a 30 percent rating and a 20 percent rating, and your combined rating is 40 percent, not 50. Nobody made a mistake.

Work it out with the calculator, or read on for why.

The idea behind the table

38 C.F.R. §4.25 treats disability as a reduction in what remains of you, not as a share of a pie.

Start at 100 percent efficient. A 30 percent disability leaves you 70 percent efficient. The next disability — 20 percent — is applied to what is left, so it takes 20 percent of that remaining 70, which is 14. Add that to the 30, and the combined value is 44.

Then one conversion: 44 to the nearest number divisible by ten is 40 percent.

That is the whole mechanism. Everything else is detail.

The order is not optional

The regulation is specific: disabilities "will first be arranged in the exact order of their severity, beginning with the greatest disability," and combined from there. Highest first, then the next, and so on.

Rounding happens once, at the very end

This is where people hand-calculate their way to the wrong answer. The regulation's own example, with three ratings of 60, 40 and 20 percent:

Note what does not happen: 76 is not rounded to 80 before the third rating is combined. §4.25(b) says the conversion "will be done only once per rating decision, will follow the combining of all disabilities, and will be the last procedure in determining the combined degree of disability."

Rounding early inflates the answer and then disappoints.

Values ending in 5 round up. A combined value of 65 becomes 70, not 60.

The bilateral factor

If you have ratings on both arms, or both legs, or paired skeletal muscles, §4.26 adds something, and it is easy to miss because it happens before everything else.

Combine the paired-extremity ratings with each other as usual, then add 10 percent of that value — added, not combined — and only then carry the result into the rest of the combination. If two bilateral ratings combine to 60, the bilateral factor adds 6, giving 66 to carry forward.

The regulation also has a provision that works in your favor: where applying the factor would lower the combined evaluation, it is not applied that way.

A bilateral diagnosis is not by itself proof that two separate compensable extremity ratings exist. The factor applies to ratings you already have on both sides.

What this page does not decide

Whether two ratings are separate in the first place. §4.25 tells you how to combine evaluations that have already been legally assigned. Whether they should be separate is a different question answered by §4.14 and by any code-specific rule — the respiratory schedule, for instance, directs a single rating for a wide range of coexisting conditions.

What you get paid. The combined rating is a percentage. The payment depends on it plus your dependents, and the rates change every year. Use VA's current compensation rate tables.

Checking a decision

Write down each granted disability and its percentage, any paired-extremity grouping, every intermediate value, and the final conversion. If your own arithmetic and VA's disagree, the gap is usually the order, the bilateral factor, or rounding too early — in that order of likelihood.

Reviewed October 6, 2026