VA Disability Ratings Explained

Why VA math is not normal math

The Department of Veterans Affairs rates each service-connected condition from 0% to 100% in 10-point steps, based on how much it impairs earning capacity. But when a veteran has more than one rated condition, the VA does not add the percentages. Instead it uses "combined ratings," a formula where each rating applies only to the percentage of the veteran that previous ratings left unimpaired.

The logic: if a 50% rating means half your earning capacity is impaired, the next condition can only impair what remains. This surprises almost everyone the first time they see it, and it is the source of nearly all "my rating should be higher" confusion. Once you see the formula worked through, it clicks permanently.

The combined ratings formula, step by step

The VA combines ratings from highest to lowest, one at a time. Start with the highest rating. For each next rating, multiply it by the remaining unimpaired percentage and add the result to the running total. When all ratings are folded in, round the total to the nearest 10%.

In formula terms, combining rating B into a running total T means: new total = T + B x (100 - T) / 100. Each step shrinks the pool the next rating can draw from, which is why combined ratings always come in lower than simple addition, and why they can never exceed 100%.

Worked example: 50%, 30%, and 20%

Take a veteran rated 50% for a back condition, 30% for a knee, and 20% for hearing loss. Sort highest to lowest and combine one at a time.

Step 1: start with 50%. Running total: 50%. Unimpaired remainder: 50%.

Step 2: fold in the 30% rating. It applies to the remaining 50%: 30% of 50 is 15. Running total: 50 + 15 = 65%. Unimpaired remainder: 35%.

Step 3: fold in the 20% rating. It applies to the remaining 35%: 20% of 35 is 7. Running total: 65 + 7 = 72%.

Step 4: round 72% to the nearest 10%: 70% combined rating. Simple addition would have said 100%; the VA formula says 70%. The 30-point gap is not an error and not something to appeal on math grounds; it is the formula working exactly as designed.

The bilateral factor, in plain English

There is one more wrinkle for disabilities affecting both sides of the body: both arms, both legs, or paired skeletal muscles. The VA treats the pair as a unit and grants a small bonus called the bilateral factor.

How it works: combine the bilateral ratings with the standard formula, take half of that combined value, and add it to the combined value before folding in any remaining non-bilateral ratings. Example: 20% left knee and 20% right knee combine to 36% (20 + 20% of 80). Half of 36 is 18, so the bilateral value is 36 + 18 = 54% going into the rest of the calculation. The factor exists because paired impairments limit a veteran more than two unrelated ones would.

What the combined rating means

The combined rating, rounded to the nearest 10%, is what the VA pays on. The VA publishes monthly compensation tables from 10% to 100% in 10-point steps, with additional amounts for veterans with a spouse, children, or dependent parents. A 0% rating is still meaningful: it establishes service connection, so if the condition worsens, the veteran can seek an increase without re-proving the connection.

Two milestones matter beyond the monthly check. At 100%, veterans gain access to additional benefits that vary by state and program. And Total Disability based on Individual Unemployability (TDIU) lets veterans who cannot maintain substantially gainful employment be paid at the 100% rate even when their combined rating is lower, typically 60% for a single condition or 70% combined. Those are separate applications with their own criteria.

Common mistakes to avoid

Adding instead of combining is the big one, and this guide exists to kill it. Combining in the wrong order is the second: always sort highest to lowest first, because the formula is order-dependent and the VA's order gives the veteran the highest legal result. Forgetting to round is third: 72% pays as 70%, and 75% rounds up to 80%, so the rounding step can be worth real money at the boundary.

Finally, confusing the rating with the payment: the rating determines which row of the pay table you are on, but dependents, cost-of-living adjustments, and special monthly compensation can move the actual check. Always verify against the current VA rate tables rather than multiplying old figures in your head.

Why new ratings barely move high combined ratings

The flip side of the combined-ratings formula is diminishing returns: the higher your combined rating, the less each new rating adds. This surprises veterans filing new claims at 80 or 90%, so work through it once and the disappointment becomes predictable math instead.

At a 90% combined rating, only 10% of you remains "unimpaired" for new ratings to act on. A new 10% rating adds 10% of 10, which is 1: total 91%, which rounds to 90%. No change. A new 20% rating adds 2: 92%, rounds to 90%. A new 30% adds 3: 93%, still 90%. It takes a new 50% rating to move the needle: 50% of 10 is 5, total 95%, which rounds up to 100%.

This has two practical consequences. First, at high combined ratings, increases to existing ratings are usually worth more than new low-rated claims, because an increase re-rates a condition that already occupies a big slice. Going from 50% to 70% on the back condition in our earlier example moves the combined total far more than adding a new 10% claim. Second, when you file anything new, the VA recomputes the entire combination from scratch, highest to lowest, so always re-run the full math rather than adding the new rating to your old total. And remember the rounding step at the end: at the boundaries, a single point can be worth a full 10% tier, which is why the exact arithmetic matters.

Key takeaways

Ratings combine; they never add: each new rating applies only to the remaining unimpaired percentage, highest to lowest. 50 + 30 + 20 = 70: work the formula (50, then 65, then 72, rounds to 70) and the mystery disappears. Bilateral disabilities get a bonus: paired conditions combine, take half again, then fold into the rest. High ratings have diminishing returns: at 90%, even a new 30% rating leaves you at 90%, so prioritize increases to existing ratings over new small claims. Always recompute from scratch when anything changes, and mind the rounding: at the boundaries, one point can be worth a full 10% tier. This guide covers the math only; for claims help, work with an accredited veterans service organization. Keep copies of every decision letter, because each one shows the combined math the VA used, and checking it yourself is the fastest way to catch an ordering or rounding mistake.