VA does not add your disability ratings together — it combines them, and then rounds. Enter your ratings below to see your real combined rating and every step of the math, including the bilateral factor for paired limbs.
Choose your ratings above and the math appears here.
Estimate only. VA's rating decision is the authoritative answer, and this does not calculate Special Monthly Compensation, TDIU, or dependent-adjusted pay.
This is an estimate for planning, not a VA decision, and not legal or medical advice. It follows 38 CFR 4.25 and 4.26, but VA's rating decision is the authoritative answer.
Free accredited help exists: VA-accredited representatives, VSOs, and County Veterans Service Officers review decisions and file claims at no cost. Never pay for basic claim help.
Why 30% and 20% is not 50%
VA does not add disability ratings together. It combines them, and the difference surprises almost everyone the first time they see it.
The logic is that ratings describe how much of a whole person is affected. Your highest rating is applied first. Every rating after that applies only to the part of you that is left. A 30% rating leaves 70% behind, so a 20% rating is worth 20% of that remaining 70% — 14 points, not 20. Thirty and twenty combine to 44.
Then 38 CFR 4.25 converts that combined value to the nearest degree divisible by 10, so 44 becomes a 40% rating. That is why adding two ratings on paper and comparing it to your decision letter almost never matches.
One detail matters if you are checking the math yourself: VA applies 4.25 through a table of whole numbers, so each pairwise combination is a whole number before the next rating is combined with it. Carrying decimals all the way to the end can change the final answer. Ratings of 50, 30, 20 and 10 combine to 65, then 72, then 75 — which rounds up to 80% — while keeping the decimals would land on 74.8 and round down to 70%. This calculator rounds at each step, the way the table does.
The order matters, and so does the bilateral factor
Ratings are always combined from most disabling to least. The calculator sorts them for you.
There is one significant exception. Under 38 CFR 4.26, disabilities affecting both arms, both legs, or paired skeletal muscles get a bilateral factor. Those disabilities are combined with each other first, then an extra 10% of that combined value is added, and only then is the result combined with the rest of your ratings.
The bilateral factor needs at least two paired-limb disabilities to apply. Marking a single row as bilateral does nothing, which the calculator will tell you.
What this calculator does not tell you
It estimates your combined rating percentage. It does not tell you what you will be paid.
Your monthly compensation depends on the rounded combined rating and on your dependents, and separate benefits can raise it — Special Monthly Compensation for specific losses, or being paid at the 100% rate through Individual Unemployability when service-connected conditions prevent substantially gainful employment. None of that is modelled here.
It also cannot tell you whether a condition should be rated higher, or whether something missing should be service-connected at all. That is a question for an accredited representative who can read your evidence.
Get your decision read by someone accredited — for free
If the number here does not match your decision letter, that is worth looking into, and you should not pay anyone to do it.
VA-accredited representatives, Veterans Service Organizations, and County Veterans Service Officers review rating decisions and file claims at no charge. Paid “claim sharks” offer nothing a free accredited representative cannot do.
Sources
This calculator implements the regulations below. Rates and rules change — check the official page before you act.