Try the math — inline calculator
- 50% takes 50% of 100 = 50 → 5050 left
- 30% takes 30% of 50 = 15 → 6535 left
- 20% takes 20% of 35 = 7 → 7228 left
Added up (wrong)
100%
Table value 72 of 100 → nearest 10, a 5 rounds up
VA combined (correct)
70%
$1,808.45 a month, 2026 rate, veteran alone · next tier 80% is $293.70 more
The bilateral factor (38 CFR § 4.26, both arms or both legs) and any TDIU bump aren’t modeled here — check your decision letter for the words “bilateral factor”, and run the full estimator for the dollar amount with a spouse, children or parents.
Prefer to watch?
About 15 minutes. Plays right here.
VA Math Explained: Why 90% Plus 40% Is Still 90% (and What Actually Gets You to 100)
Watch on YouTube →The whole-person theorem
The VA models your body as a 100-point pool of ability. Your first rated condition takes a slice. Your second takes a slice of what’s LEFT. Your third takes a slice of what’s left after that. The pool can never go below zero.
Worked example: 50% + 30% + 20%.
- Start with 100 points of ability remaining.
- 50% of 100 = 50 points lost. Pool is now at 50.
- 30% of 50 = 15 points lost. Pool is now at 35.
- 20% of 35 = 7 points lost. Pool is now at 28.
- You’ve lost 100 − 28 = 72 points of ability. The VA rounds to the nearest 10 → 70%.
Why your 5th condition often doesn’t matter
After three or four conditions, the remaining pool is small. Adding a 10% rating to a vet whose pool is at 25 only takes 2.5 points away. They were 75 combined; they’re still 75 combined after rounding.
The strategic implication: order the conditions you push hardest by which would BE rated highest first. A solid 50% PTSD claim does far more for your combined than a solid 10% scar claim, because the 50% condition lands first in the math.
The bilateral factor
Conditions affecting paired body parts (both knees, both hands, both ears, both eyes) get a 10% bonus on the COMBINED rating of the pair, added BEFORE that pair is combined with the rest of your conditions.
Worked example: 20% right knee + 20% left knee.
- Combine 20% + 20% using the whole-person theorem: 20% of 100 = 20, plus 20% of 80 = 16. Total 36 points lost → pool is 64.
- Bilateral bonus: 10% of the 36 lost = 3.6 extra points lost. Pool is now 60.4.
- Round the bonused-pair (40) and CARRY it forward for combination with non-bilateral conditions.
The rounding rule
The VA rounds the final combined to the nearest 10%, NOT the ratings of individual conditions. 24 rounds to 20. 25 rounds to 30. 74 rounds to 70. 75 rounds to 80. One more thing the table does that a calculator does not: each step of the walk is read off VA's own combined-ratings table (38 CFR § 4.25), which prints whole numbers — 72 combined with 10 is 74.8 on a calculator but 75 on the table, and that 75 then rounds up to 80. Our estimator walks the table's numbers, not the decimals. The exact half-point cutoffs are why pushing one condition from 38% to 41% can move your combined from 70% to 80% — you crossed a rounding boundary.
Why this matters strategically
- Pushing a single condition up a tier can be worth more than adding two new low-rated ones.
- Bilateral pairs are leverage. Both knees rated 20% beats one knee rated 30% and one knee rated 10% by a lot.
- Vets just under a rounding boundary should fight hard for any extra evidence — a single percentage point can be worth a tier.
- When the pool is low, secondary conditions (sleep apnea secondary to PTSD, migraines secondary to TBI) are still worth claiming for SMC stacking and TDIU eligibility, even if they don’t move the combined number.