VA Math: Combined Disability Ratings
Overview
The VA calculates combined disability ratings using a process that confuses many veterans because it doesn't use simple addition. Understanding VA math is essential for predicting your combined rating.
Chief's Take: VA Math is where 10+10=19. Don't use a calculator—use the table. If you try to do this in your head, you will have an aneurysm. The VA starts with your highest rating and takes percentages of what's left. It's not fraud, it's just... math from another dimension.
Key Concept: Total Person Approach
Rather than adding percentages together, the VA uses a "total person" concept. The calculation begins with 100% (representing a whole, healthy person) and each condition removes a percentage from what remains.
VA math starts everyone off being considered 100%, then each condition takes a fraction of what is left.
How the Calculation Works
Step-by-Step Process
- Order ratings from highest to lowest
- Start with 100% (the whole person)
- Apply the highest rating first
- Apply each subsequent rating to what remains
- Round final result to nearest 10%
Example Calculation
A veteran with 60%, 40%, and 20% ratings:
- Start with 100%
- Apply 60%: 100 × 0.60 = 60% disability, leaving 40% healthy
- Apply 40% to remaining: 40 × 0.40 = 16% additional disability
- Combined so far: 60% + 16% = 76%, leaving 24% healthy
- Apply 20% to remaining: 24 × 0.20 = 4.8% additional disability
- Total: 76% + 4.8% = 80.8%
- Round to nearest 10%: 80%
Quick Formula
For two ratings A and B: Combined = A + B × (1 - A)
For example, 60% + 40%: = 0.60 + 0.40 × (1 - 0.60) = 0.60 + 0.40 × 0.40 = 0.60 + 0.16 = 0.76 or 76%
Combined Ratings Table
The VA provides a combined ratings table for quick calculations. To use it:
- Find the highest percentage in the left column
- Cross-reference with the next highest percentage across the top
- The intersection gives your combined rating before rounding
- Use that number as your new starting point for additional conditions
- Repeat until all conditions are combined
- Round the final result
Bilateral Factor Addition
When disabilities affect both sides of the same paired extremity (arms or legs), an additional 10% is added to the bilateral combination before combining with other ratings.
How Bilateral Factor Works
- Combine the ratings for both sides using VA math
- Add 10% to that combined number
- Then combine with remaining conditions
Example
Left knee 30% + Right knee 20%: 1. Combine: 30% + 20% = 44% 2. Add bilateral factor: 44% × 1.10 = 48.4% 3. Round: 48% 4. Combine this 48% with other conditions
Bilateral Factor Limitations
- Both sides must be rated at least 10% (compensable)
- Hearing disabilities don't qualify
- Eye disabilities don't qualify
- Certain scarring types have restrictions
- Cranial nerves don't qualify
Rounding Rules
- 0.5% or higher rounds up
- Less than 0.5% rounds down
- Final combined rating always rounds to nearest 10%
Rounding Examples
| Calculated | Rounded To |
|---|---|
| 74% | 70% |
| 75% | 80% |
| 94% | 90% |
| 95% | 100% |
Special Situations
Zero Percent Ratings
- Two or more conditions rated at 0% may qualify for 10% payment if they impair employment
- This special consideration ends if the veteran later receives a 10%+ rating
94% Rule (April 2023 Update)
If bilateral factors cause the combined rating to round down from 95% to 94%, the VA may disable the bilateral factor calculation to achieve 100%.
Protected Ratings
Certain ratings have special protections: - 100% rating held for 20+ years cannot be reduced - Ratings held for 5+ years require more evidence to reduce - See "Rating Reductions" for full protection rules
Common Combined Rating Results
| Two Ratings | Combined (unrounded) | Final |
|---|---|---|
| 50% + 50% | 75% | 80% |
| 60% + 40% | 76% | 80% |
| 70% + 30% | 79% | 80% |
| 50% + 40% | 70% | 70% |
| 40% + 40% | 64% | 60% |
| 30% + 30% | 51% | 50% |