VA Math Explained: How the VA Combines Disability Ratings
If you have two or more disability ratings, the VA doesn't just add them together. Here's the plain-English math, why 50% + 30% isn't 80%, and worked examples you can check your own numbers against.
Combined ratings are not simple addition. This guide explains the 38 CFR 4.25 table, required ordering, and final rounding rule.
Why 50% + 30% Doesn't Equal 80%
The VA uses what's called combined ratings math. Instead of adding percentages, each rating is applied to the portion of you the VA still considers healthy. The idea: you can never be more than 100% disabled, so each new rating takes a bite out of what's left, not the whole.
Apply 50% rating → 50% of 100 = 50 used. 50% healthy remains.
Apply 30% rating → 30% of 50 = 15 used. 35% healthy remains.
Total used: 50 + 15 = 65 → rounds to 70%
So a veteran with a 50% and a 30% rating ends up at 70% combined, not 80%. That rounding step matters too — the VA rounds the combined value to the nearest 10%.
The 4 Steps of VA Combined Ratings Math
Worked Example: Three Ratings (40%, 30%, 20%)
100 − 40 = 60 healthy. Total used: 40
30% of 60 = 18. Total used: 40 + 18 = 58. (42 healthy)
20% of 42 = 8.4. Total used: 58 + 8.4 = 66.4, which Table I carries as 66
Round 66 → 70% combined
Three ratings that "add up" to 90% on paper combine to a 70% rating in reality. This is exactly why a calculator helps.
What Your Combined Rating Is Worth in 2026
Your combined rating determines your monthly tax-free compensation, which also varies by your number of dependents. Because these dollar figures are set by the VA and updated annually, the most reliable way to see your current estimate is to run your specific ratings and dependent situation through a calculator built on the latest published rates.
The Transition OPS calculator estimates a combined rating using 38 CFR 4.25. VA determines the official rating and payment.
Common Questions
Does the order of my ratings change the result?
Enter ratings from highest to lowest. That is the order required by 38 CFR 4.25, and the calculator should follow it automatically.
What is the "bilateral factor"?
If you have disabilities affecting both arms, both legs, or paired skeletal muscles, 38 CFR 4.26 adds a step. The right- and left-side ratings are combined first, in the normal way. Then 10 percent of that combined value is added — added, not combined — and only then does that result go on to be combined with your other ratings, treated from that point as a single disability.
The worked examples on this page do not apply the bilateral factor, because it depends on which of your specific ratings are paired. If any of yours qualify, VA must apply the bilateral factor before combining with other ratings; the final rounded evaluation may or may not change. That is a question for a VSO or CVSO with your rating decision in hand.
Where does this leave me for benefits?
Your combined rating affects compensation, healthcare priority, and eligibility for programs across your transition. Tracking it alongside your other deadlines — BDD claim windows, separation health assessment, TRICARE transition — is exactly what Transition OPS is built to do.
About Transition OPS
Transition OPS is a free progressive web app for transitioning service members, veterans, and Guard/Reserve members across all branches. It covers VA math and pay estimation, SkillBridge employer intel, benefits deadlines timed to your separation date, state tax intelligence, and policy alerts verified against primary sources. No ads, no login, no paywall — built by a veteran.