5 min read · Education
Combined ratings explained — why 60 + 30 ≠ 90
A vet sees four conditions on their rating decision — 50%, 30%, 20%, 10% — adds them up to 110%, and is told their combined rating is 70%. The math seems insulting. It isn’t random; it’s a 75-year-old formula based on what’s left of you, not what’s broken.
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%.
Try the math — inline calculator
Naive sum (wrong)
100%
VA combined (correct)
70%
The bilateral factor and any TDIU bump aren’t modeled here — run the full estimator for those plus your 2026 monthly dollar amount with dependents.
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. 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.