How Does VA Math Work? Why 50% + 30% + 10% Is Not 90% (2026)
Quick answer
VA ratings do not add; they combine. Under 38 CFR §4.25 the VA applies each rating, highest first, to the efficiency you have left. A 50% rating leaves 50 points; 30% of that 50 is 15, for 65; 10% of the remaining 35 is 3.5, rounded to 4, for 69. The VA rounds 69 to the nearest ten: 70%. In 2026 that pays $1,808.45 a month for a veteran alone, versus $2,362.30 at 90%.
The Whole-Person Rule Behind VA Math
The combined-ratings table in 38 CFR §4.25 is built on a single idea: a veteran starts at 100% efficient, and each service-connected condition takes a percentage of whatever efficiency remains. The result is always less than the arithmetic sum, and the gap grows as the ratings get higher.
Here is the procedure the VA rater follows, and the one the VA disability rating calculator reproduces step by step:
- Sort every compensable rating from highest to lowest.
- Start with the highest rating. That is your running combined value.
- For the next rating, take that percentage of (100 minus the running value), add it, and round to a whole number. Repeat for every rating.
- Round the final whole number to the nearest 10. Values ending in 5 round up (75 becomes 80%, 74 becomes 70%).
The whole-number rounding at each step is what the printed §4.25 table does, and it can help or hurt you by a point; the calculator shows that whole-number value before the final rounding so you can see exactly where you stand.
The Worked Example: 50% + 30% + 10%
Take a veteran with PTSD at 50%, a lumbar strain at 30%, and tinnitus at 10%. Addition says 90%. VA math says otherwise.
| Step | Rating applied | Efficiency remaining before | Points added | Running combined value |
|---|---|---|---|---|
| 1 | 50% | 100 | 50.0 | 50 |
| 2 | 30% | 50 | 15.0 | 65 |
| 3 | 10% | 35 | 3.5, rounds to 4 | 69 |
| Final | Round to nearest 10 | 70% |
The 2026 dollar consequence, using the va.gov rate table effective December 1, 2025 (a 2.8% COLA), for a veteran with no dependents:
- Combined 70%: $1,808.45 a month, $21,701.40 a year, tax-free.
- The 90% the veteran expected: $2,362.30 a month, $28,347.60 a year.
- The difference: $553.85 a month, or $6,646.20 a year.
This veteran is at 69, and the next step (80%) requires a whole-number value of 75: 6 points away with only 31 points of efficiency left. A new 10% rating adds 10% of 31, or 3.1 points, landing at 72 and changing nothing. A new 20% rating adds 6.2 points, landing at 75, which rounds up to 80% and $2,102.15 a month, a raise of $293.70. The same 20% condition worth $356.66 on its own is worth $293.70 here, and a 10% condition is worth $0. Run your own numbers in the VA disability rating calculator to find out how many points you are from the next step and which rating size actually crosses it.
Why Each New Condition Is Worth Less as You Climb
Because every rating is applied to the remaining efficiency, the marginal value of a rating falls as your combined value rises. Here is what a single new 10%, 20% or 30% rating adds at different starting points.
| Starting combined value | +10% rating adds | +20% rating adds | +30% rating adds |
|---|---|---|---|
| 40 | 6 points, to 46 | 12, to 52 | 18, to 58 |
| 60 | 4, to 64 | 8, to 68 | 12, to 72 |
| 80 | 2, to 82 | 4, to 84 | 6, to 86 |
| 90 | 1, to 91 | 2, to 92 | 3, to 93 |
| 94 | 1, to 95 (rounds to 100%) | 1, to 95 | 2, to 96 |
Two things fall out of this table. At a whole-number value of 90 you have exactly 10 points left, so reaching the 95 that rounds to 100% needs a new rating of at least 50%. And step rounding means a veteran at 94 gets to 100% with a single 10% rating, while a veteran at 90 does not get there with a 40%. Your exact whole-number value matters far more than the percentage on your award letter.
Common pairings, for sanity-checking a decision letter: 30% + 30% = 51 (50%); 50% + 50% = 75 (80%); 70% + 50% = 85 (90%); 90% + 40% = 94 (still 90%); 90% + 50% = 95 (100%).
The Bilateral Factor: The One Place VA Math Gives You Extra
38 CFR §4.26 is the exception that works in the veteran's favor. When you have compensable ratings on both arms, both legs, or paired skeletal muscles, the VA combines those paired ratings first, adds 10% of that combined value, and treats the result as a single rating in the main combination.
Take the calculator's default example: a left knee at 20% and a right knee at 10%. Combined, they are 20 + (10% of 80) = 28. Add 10% of 28, or 2.8, for a bilateral value of 30.8, which is then slotted into the severity-ordered list alongside the PTSD (50%), back (30%) and tinnitus (10%) from the earlier example:
| Step | Rating applied | Efficiency remaining | Points added | Running value |
|---|---|---|---|---|
| 1 | 50% | 100 | 50.0 | 50 |
| 2 | 30.8% (bilateral) | 50 | 15.4 | 65 |
| 3 | 30% | 35 | 10.5 | 76 |
| 4 | 10% | 24 | 2.4 | 78 |
| Final | Round to nearest 10 | 80% |
The factor typically adds 1 to 3 points, exactly the size that pushes a 64 across the 65 line or a 74 across 75. If your decision letter lists paired-limb conditions and never mentions §4.26, ask your VSO.
What 2026 Combined Ratings Pay
The 2026 monthly rates for a veteran with no dependents, effective December 1, 2025, are the figures the calculator uses:
| Combined rating | 2026 monthly (alone) | Annual, tax-free |
|---|---|---|
| 10% | $180.42 | $2,165.04 |
| 20% | $356.66 | $4,279.92 |
| 30% | $552.47 | $6,629.64 |
| 40% | $795.84 | $9,550.08 |
| 50% | $1,132.90 | $13,594.80 |
| 60% | $1,435.02 | $17,220.24 |
| 70% | $1,808.45 | $21,701.40 |
| 80% | $2,102.15 | $25,225.80 |
| 90% | $2,362.30 | $28,347.60 |
| 100% | $3,938.58 | $47,262.96 |
Notice the shape: the jump from 90% to 100% ($1,576.28 a month) is larger than the entire climb from 10% to 60% ($1,254.60), which is why VA math at the top end matters so much. From 30% upward, dependents add to these figures: a spouse adds $65 at 30%, $153 at 70%, and $219.59 at 100%; a first child adds $44, $102 and $146.85. At 10% and 20% there are no dependent add-ons at all.
What VA Math Means for Your Claims Strategy
The arithmetic points to three practical conclusions.
Claim secondary conditions early, while each one is still worth something. Sleep apnea secondary to PTSD and radiculopathy secondary to a back rating are the most common unclaimed ratings. At a combined value of 40 a new 30% rating adds 18 points; at 80 it adds 6.
Know your whole-number value, not just your rounded rating. A veteran at 74 and a veteran at 66 are both "70%," but the first needs one point and the second needs nine.
Check the TDIU threshold before chasing 100% schedular. Under 38 CFR §4.16(a), one rating of at least 60%, or a combined rating of at least 70% with one rating of at least 40%, meets the schedular threshold for Total Disability based on Individual Unemployability, which pays the 100% rate if the conditions prevent substantially gainful employment. The 80% veteran in the knee example already qualifies on paper, and the calculator's verdict flags this automatically.
Finally, the money is tax-free. A $21,701 benefit at 70% is worth about $27,800 of wages in the 22% federal bracket, before state tax, and it uses none of your 2026 standard deduction ($16,100 single, $32,200 married filing jointly). That pairs well with Roth TSP contributions; the military TSP contribution calculator shows how much of the $24,500 elective deferral limit you can fund.
FAQ
Q: Why does the VA round 69 down to 70% but 75 up to 80%?
38 CFR §4.25 rounds the final combined value to the nearest number divisible by 10, and values ending in 5 are adjusted upward. So 65 through 74 all become 70%, and 75 through 84 become 80%. Only the final value is rounded this way; intermediate steps round to the nearest whole number.
Q: What is the highest combined rating I can get without a single 100% condition?
Any combination whose whole-number value reaches 95 rounds to 100%. Practical examples: 90% + 50% works (90 + 5 = 95); 80% + 70% alone does not (80 + 14 = 94, still 90%), but 80% + 70% + 20% does (94 + 1.2 rounds to 95). The calculator shows how many points you need from your current value.
Q: Is a 10% rating ever worth claiming if I am already at 80%?
At a whole-number value of 80 a 10% rating adds 2 points, and you need 5 to reach 90%, so on its own it changes nothing. It pays off when your value is already 83 or 84, or when the condition is a paired-limb rating that triggers the §4.26 bilateral factor.
Q: How much does 70% pay with a spouse and two children under 18 in 2026?
$1,808.45 base, plus $164 for a spouse with a child, plus $102 for the first child, plus $76 for the second child under 18, for $2,150.45 a month. The same family at 90% receives $2,802.30, and at 100% $4,428.10.
Q: Will VA math change when the rates go up on December 1, 2026?
No. The combined-ratings table in §4.25 and the bilateral factor in §4.26 are regulations that do not change with the annual COLA. Only the dollar amounts in the rate table change, by the same percentage as the Social Security cost-of-living adjustment.