How the VA Combined Ratings Formula Works — and Why 70% + 30% ≠ 100%
One of the most common points of confusion in VA disability is the combined ratings formula. Veterans with multiple service-connected conditions don't simply add their percentages together — and that surprises almost everyone. Here's how it actually works, why, and what it means for your compensation.
The Key Concept: "Whole Person" Theory
The VA uses what it calls the "whole person" theory of disability. The idea is that a person cannot be more than 100% disabled — so you can't simply add disabilities together past a whole person. Each additional disability reduces the remaining "healthy" portion of the person, not the whole person.
Mathematically:
- Start with a "whole person" = 100 efficiency
- The first disability reduces efficiency by that percentage
- The second disability is applied to the remaining (not original) whole person
- And so on
The Formula, Step by Step
Example: 70% + 30% combined
- Start: 100 whole person
- Apply 70% disability: 100 × 0.70 = 70 points of disability. Remaining efficiency: 100 − 70 = 30
- Apply 30% disability to the remaining 30: 30 × 0.30 = 9 additional points. Total: 70 + 9 = 79 points
- Round to nearest 10%: 80% combined rating
So 70% + 30% = 80% combined, not 100%.
Why the VA Rounds the Way It Does
After calculating the combined value (79 in the example above), the VA rounds to the nearest 10%:
- Values ending in 1–4 round down (e.g., 79 → 70% — wait, actually 79 rounds to 80%)
Correction: the VA first combines to get a raw number, then rounds to the nearest 10:
- 1–4: round down. Example 74 → 70%
- 5–9: round up. Example 75 → 80%
One exception: If the final combined value, before rounding, is 45 or higher — it rounds to 50%. This "magic number" rule is important.
Combined Ratings Table: Common Examples
| Disabilities | Combined (VA formula) | VA Rating |
|---|---|---|
| 10% + 10% | 19 | 20% |
| 30% + 20% | 44 | 40% |
| 50% + 30% | 65 | 60% |
| 60% + 20% | 68 | 70% |
| 70% + 30% | 79 | 80% |
| 70% + 50% | 85 | 90% |
| 70% + 30% + 10% | 81 | 80% |
| 80% + 40% | 88 | 90% |
| 90% + 20% | 92 | 90% |
| 90% + 10% | 91 | 90% |
Note: The VA uses the Combined Ratings Table in 38 CFR Part 4, Appendix A. You can calculate your own using the TAP-OS VA Disability Calculator.
Order of Combination Matters
The VA always combines disabilities in descending order — highest rating first. This produces the highest possible combined value. If you received ratings out of order, the VA is required to re-sort before combining.
Example: 30% + 50% + 20%
Sort: 50%, 30%, 20%
- 50%: 100 × 0.50 = 50 disability, 50 remaining
- 30% applied to 50 remaining: 50 × 0.30 = 15 more → total 65, 35 remaining
- 20% applied to 35 remaining: 35 × 0.20 = 7 more → total 72
- Round: 70%
Why Can't I Reach 100%?
Because the formula approaches 100% asymptotically — each new condition reduces a smaller and smaller remaining slice. Mathematically, you can never reach 100% through the combined ratings formula alone.
In practice, the highest combined rating achievable through the formula before rounding to 100% requires very high multiple ratings. For example, a veteran needs a combined value of 95 or higher to round to 100%.
This is why VA created TDIU (Total Disability based on Individual Unemployability) — a way to receive 100% compensation without meeting the 100% schedular threshold. See below.
The "Plateau" Problem at 90%
Many veterans reach a combined rating of 90% and find it extremely difficult to get to 100% through additional claims. The math shows why:
| Additional Rating Added to 90% | Combined Value | VA Rating |
|---|---|---|
| +10% | 91 | 90% |
| +20% | 92 | 90% |
| +30% | 93 | 90% |
| +40% | 94 | 90% |
| +50% | 95 | 100% |
A veteran at 90% would need an additional condition rated at 50% or higher to reach 100% schedular. This is hard to achieve without a single high-value condition like PTSD at 70%, or sleep apnea combined with additional conditions.
The practical solution: If you're at 90% and unable to maintain substantially gainful employment, file for TDIU.
TDIU: Reaching 100% Compensation Without 100% Schedular Rating
Total Disability based on Individual Unemployability (TDIU) pays the same compensation rate as 100% while your combined rating is below 100%. You must meet one of two criteria:
| Option | Requirements |
|---|---|
| 38 CFR § 4.16(a) (standard) | ONE condition at 60%+, OR combined rating of 70%+ with at least one condition at 40%+ |
| 38 CFR § 4.16(b) (extraschedular) | Any veteran unable to maintain substantially gainful employment, even without meeting the above thresholds |
For TDIU, you must also demonstrate that you cannot maintain substantially gainful employment — defined by the VA as work earning above the federal poverty threshold. Part-time, sheltered, or marginal employment generally does not disqualify you.
In 2026, TDIU pays the same monthly compensation as a 100% rating ($3,927.08/month for a single veteran with no dependents).
Bilateral Factor
When a veteran has disabilities of paired extremities (both arms, both legs, or combinations), the VA applies a bilateral factor — an upward adjustment — before combining that pair with other disabilities.
How it works:
- Combine the ratings for the paired extremities using the standard formula
- Add 10% of that combined value as the bilateral factor (round to nearest 5%)
- Use that adjusted value as a single combined rating, then combine with remaining conditions
Example: 30% right knee + 20% left knee
- Combined: ~44% → 40%
- Bilateral Factor: 40% × 0.10 = 4% → rounds to 5%
- Bilateral value used: 45%
- This 45% then combines with other conditions
This is a free rating boost — always identify bilateral conditions and ensure they're rated together.
Pyramiding: The Rules Against Double-Counting
The VA's anti-pyramiding rule (38 CFR § 4.14) prohibits rating the same disability twice under different diagnostic codes. For example:
- You cannot rate a knee scar and the underlying knee condition both from the same injury if they affect the same function
- You can separately rate a scar if it affects a different function (e.g., the scar itself causes pain separate from range of motion limitation)
However, separate and distinct conditions from the same event can be separately rated. A back injury that causes (1) lumbar strain, (2) radiculopathy in the left leg, and (3) radiculopathy in the right leg may be rated as three separate conditions. Understanding pyramiding versus legitimate separate ratings is crucial for maximizing your compensation.
Key Takeaways
- The VA does not simply add percentages together — it uses the whole person formula
- Disabilities are combined highest to lowest to maximize the result
- The formula makes it harder to reach 100% as your combined rating increases
- At 90%, you need a 50%+ additional condition to reach 100% schedular
- TDIU provides 100%-equivalent pay if you can't maintain substantially gainful employment
- The bilateral factor adds a bonus for paired extremity disabilities — always claim bilateral conditions together
- Anti-pyramiding limits double-counting, but separate conditions from the same event can often be separately rated
Use the TAP-OS VA Disability Calculator to calculate your actual combined rating.
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