VA Math: How Your Combined Rating Is Calculated

You open the decision letter. Two conditions granted: 50% for one, 30% for the other. And the combined rating at the bottom says 70%.

Nobody made an arithmetic error. That is the correct answer, and it comes out of a table published in the regulations that has worked this way for decades. But almost nothing about the decision letter explains it, so a large number of veterans read that line as VA quietly shorting them ten points.

This article is about that math and nothing else. It assumes you already know the shape of the process — if you don't, VA Claims 101 covers filing end to end, and secondary conditions covers how veterans most often add ratings to an existing one. What follows is how the percentages you've been granted turn into the single number that decides what you're paid.

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The Whole-Person Idea

The rule that governs this is 38 CFR § 4.25, and its opening lines give away the whole logic:

Thus, a person having a 60 percent disability is considered 40 percent efficient. Proceeding from this 40 percent efficiency, the effect of a further 30 percent disability is to leave only 70 percent of the efficiency remaining after consideration of the first disability, or 28 percent efficiency altogether. The individual is thus 72 percent disabled.

That is the entire system in three sentences. VA is not adding up injuries. It is tracking how much of a working person is left.

Your first and most severe condition takes its percentage out of a whole person. The next condition cannot also take a bite out of a whole person, because there isn't a whole person there anymore — it takes its percentage out of what remains. A 30% condition is worth 30 points to a veteran with nothing else. To a veteran already rated 60%, it is worth 30% of the remaining 40, which is 12.

This is why ratings never quite add up, and why they can never reach 100% by accumulation alone. Each new condition applies to a smaller and smaller remainder.

Whether you find that fair is a separate question, and plenty of veterans don't. But it is not a glitch and it is not discretionary — a rater has no authority to add your percentages together instead.

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Two Conditions, Worked Through

Take the 50% and 30% from the decision letter above.

Start with the higher one. You are 50% disabled. Half of you is left.

Apply the second to what's left. The 30% condition takes 30% of that remaining 50 — which is 15.

Add that to the first. 50 + 15 = 65.

Sixty-five is your combined value. It is not yet your rating, because ratings only exist in multiples of ten. Section 4.25(a) converts it: the combined value goes "to the nearest number divisible by 10, and combined values ending in 5 will be adjusted upward."

Sixty-five ends in 5, so it goes up to 70%.

The regulation works this exact example itself. It also works one that goes the other way:

Similarly, with a disability of 40 percent, and another disability of 20 percent, the combined value is found to be 52 percent, but the 52 percent must be converted to the nearest degree divisible by 10, which is 50 percent.

Forty and twenty combine to 52, and 52 rounds down to 50. Those two veterans — one at 65, one at 52 — are thirteen points apart in the arithmetic and twenty points apart on the check.

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The Rounding Rule, and the Part That Trips People

Two things about that conversion are worth holding onto, because they cause most of the confusion.

It happens once. Not once per condition — once per decision, at the very end. Section 4.25(b) is explicit:

The conversion to the nearest degree divisible by 10 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.

If you round as you go, you inflate your own expectations. A veteran with 50%, 30% and 20% who rounds the first pair to 70 and then combines the 20 gets 76, and reads that as 80%. Done correctly, 50 and 30 combine to 65, and 65 combined with 20 is 72 — which converts to 70%. Same three conditions, a whole band apart, purely from rounding early.

The intermediate values are whole numbers. Table I in § 4.25 is a printed grid, and every cell in it is a whole number. A rater reads a value out of the table and carries that value into the next lookup. There are no decimals travelling through the calculation, which is why the regulation can say the conversion happens exactly once.

For three or more conditions, the regulation shows the sequence:

Thus, if there are three disabilities ratable at 60 percent, 40 percent, and 20 percent, respectively, the combined value for the first two will be found opposite 60 and under 40 and is 76 percent. This 76 will be combined with 20 and the combined value for the three is 81 percent. This combined value will be converted to the nearest degree divisible by 10 which is 80 percent.

Sixty and forty give 76. Seventy-six and twenty give 81. Eighty-one converts to 80%. One conversion, at the end.

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Does the Order Matter?

Section 4.25(a) requires the conditions to "first be arranged in the exact order of their severity, beginning with the greatest disability." That instruction is about how the table is read, not a lever that changes your outcome.

The underlying arithmetic is symmetric. Combining 50 with 30 and combining 30 with 50 both give 65 — the formula produces the same number in either direction, and that holds however many conditions you have.

So there is no ordering trick, and nobody can reshuffle your conditions to manufacture a higher rating. The order matters for exactly one thing, which the next section gets to: where a bilateral group sits in the queue once it has been given its extra 10%.

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The Bilateral Factor: the One Place the Math Bends Toward You

Everything so far works against accumulating a high rating. Section 4.26 is the exception, and it is the single most commonly missed piece of rating math.

If you have compensable disabilities of both arms, both legs, or paired skeletal muscles, VA combines the paired ratings first and then adds an extra 10% of that combined value on top:

…the ratings for the disabilities of the right and left sides will be combined as usual, and 10 percent of this value will be added (i.e., not combined) before proceeding with further combinations, or converting to degree of disability.

The words "added" and "not combined" are doing real work there. Ten percent of the paired value goes on as a flat addition — it does not get run through the whole-person table like everything else. That is the only place in this entire system where something is genuinely added.

Four details decide whether it applies to you:

• Both sides have to be involved. Two conditions on the same leg get nothing. Section 4.26(c) says the factor "is not applicable unless there is partial disability of compensable degree in each of 2 paired extremities" — so you need a compensable rating on the left and on the right.
• It doesn't have to be the same body part. Section 4.26(a) treats "arms" and "legs" as the whole upper and lower extremity. The regulation's own illustration pairs a right thigh condition with a left foot condition — different joints, different diagnoses, factor still applies.
• The group then travels as one condition. Once the 10% is added, the result is "treated as one disability for the purpose of arranging in order of severity and for all further combinations." It takes its place in the queue at its new, higher value.
• It can never cost you. Section 4.26(d) requires that if including a bilateral disability in the group would produce a lower combined evaluation than leaving it out, VA removes it and combines it separately — the arrangement has to be the one most favorable to the veteran.

The regulation's own worked example

Section 4.26 runs a full case. A veteran rated 60%, 20%, and 10% and 10% for a bilateral pair:

Step	Value
The two 10% ratings combine as usual	19
Add 10% of 19 (1.9) — added, not combined	20.9, carried in as 21
Order of severity: 60, 21, 20	—
60 combined with 21	68
68 combined with 20	74
Convert once, to the nearest ten	70%

Run those same four ratings without pairing the two 10s and they also come to 74, and also convert to 70%. That is worth being honest about: the factor is 10% of a paired value, not 10 rating points, and on a small pair it often moves the combined value a point or two without moving the band.

Where it changes the answer is when the pair itself is substantial. Consider a veteran with a 30% rating in each knee and nothing else:

• Paired: 30 and 30 combine to 51, plus 10% of 51 — 5.1 — gives 56. Converted: 60%.
• Unpaired: 30 and 30 combine to 51. Converted: 50%.

Identical conditions, a full band apart, entirely on whether § 4.26 was applied. That is why it is worth checking whether your decision applied it at all — the code sheet shows a bilateral entry when it did.

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Why the Last Ten Points Are So Much Harder Than the First

Because each condition applies only to the remainder, the same 10% rating is worth wildly different amounts depending on where you already are.

Your combined value	What a new 10% condition adds
0	10 points
30	7 points
50	5 points
60	4 points
70	3 points
80	2 points
90	1 point

A veteran at 90 who gets a new 10% condition granted moves to 91 — and 91 still converts to 90%. Nothing changes on the check.

The threshold arithmetic is stark. To convert to 100%, a combined value has to reach 95. A veteran at exactly 90 therefore needs a single new 50% condition to get there: 90 plus 50% of the remaining 10 is 95. Anything less than 50% leaves them at 90%.

This is also where the money stops being proportional. At 2026 rates, a veteran alone at 80% receives $2,102.15 a month and at 90% receives $2,362.30 — about $260 more. The step from 90% to 100% is $3,938.58, a jump of over $1,570 a month. The last band is worth six times the one before it, which is exactly why it is the hardest to reach and the most contested.

Two things exist because of that wall:

• TDIU. If your service-connected conditions prevent you from maintaining substantially gainful employment, § 4.16 allows payment at the 100% rate without a 100% schedular rating. Section 4.16(a)'s usual thresholds are one disability at 60% or more, or a combined rating of 70% with at least one condition at 40%. It is not automatic at those numbers — the unemployability itself has to be established. Below the thresholds, § 4.16(b) permits referral for extraschedular consideration.
• Special monthly compensation. SMC under § 3.350 is paid in addition to the schedular rate for specific losses and levels of care. It sits outside the combined rating entirely, which is why it never shows up in this arithmetic.

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What the Combined Rating Doesn't Tell You

It is not a percentage of anything. A 70% rating is not 70% of your former income, or 70% of some maximum, or 70% of a whole. It is a row in a payment table. VA publishes the monthly figures, they change with the annual COLA, and they rise very unevenly between bands. Reading the rating as a proportion of anything will mislead you about what the next ten points are worth.

More conditions do not automatically mean a higher rating. Under § 4.14, "the evaluation of the same disability under various diagnoses is to be avoided" — VA will not pay twice for the same symptoms under two names. This bites hardest in mental health, where every diagnosis is evaluated under one General Rating Formula, so a second mental-health condition generally raises the single evaluation rather than producing a second one. The added symptoms still count; they just count in one place.

Your exact combined value matters more than your rating. Two veterans both rated 70% can be in completely different positions: one at a combined value of 65, the other at 74. An 80% rating needs a combined value of 75, so the first veteran is ten points away and the second is one. Your decision's code sheet shows the exact value, and it is the single most useful number for judging whether pursuing another condition would actually change anything.

Each condition's percentage is appealable on its own. A combined rating you disagree with is usually an argument about one underlying evaluation, not about the arithmetic — the arithmetic is fixed. If a condition was evaluated below what the criteria describe, that specific evaluation is the thing to challenge. Your three appeal options covers which review lane fits which problem, and the one-year clock that governs all of them.

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Common Questions

Why didn't my rating change when a new condition was granted? Almost always because the new condition's contribution didn't cross a conversion threshold. A 10% grant on top of a combined 82 gives 84, which still converts to 80%. The condition is service-connected and on the record — it just didn't move the band. It may matter later, when the next one is added.

Can I go above 100%? Not on the schedular rating; the combined value is capped at 100. But SMC is paid on top of it, and it is common for a veteran at 100% to receive more than the 100% base rate for that reason.

Does a 0% rating do anything? It doesn't pay, and it contributes nothing to the combined value. It still establishes service connection, which means it can be increased later without proving the connection again, and it can support a secondary claim.

My VSO's number and mine don't match. Who's wrong? Usually neither — you're rounding at different points, or one of you is applying the bilateral factor and the other isn't. Rerun it combining strictly from the highest rating down, converting only once at the very end.

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The Bottom Line

The combined rating is not a score and not a sum. It is a running measure of how much of a whole person the regulations consider is left, and every condition you add gets measured against a smaller remainder than the one before it.

Understanding it won't raise your rating. What it will do is tell you where you actually stand — whether you're one point from the next band or nine, whether a paired condition would trigger the bilateral factor, and whether that next claim is worth the months it will take. That is a strategic question, and you cannot answer it without knowing the exact combined value behind your percentage.

Find it on your code sheet. Then the math above tells you the rest.

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Tools on Legatus

• Rating Calculator — combine your ratings with the bilateral factor and the official conversion, step by step
• Condition Guides — the rating criteria each individual evaluation is assigned under
• Effective Date Calculator — when a rating starts paying, which decides back pay
• VSO Finder — accredited representatives who help at no cost

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This article is general information about how VA combines disability ratings, not legal advice. The regulations quoted here were checked against 38 CFR in August 2026; compensation figures are the rates effective December 1, 2025 and change with the annual COLA. For a specific claim, work with an accredited VSO, attorney, or claims agent.