One of the most frustrating and confusing parts of the VA disability system is combined ratings. Veterans look at their individual ratings — 50%, 30%, 20% — add them up to 100%, and then receive a letter saying their combined rating is 72%. What happened?
The answer is "VA math" — and once you understand how it works, you'll understand why adding more ratings always helps your pay, even when the math seems to work against you.
The VA does not add your ratings together. Instead, it treats you as a "whole person" of 100% and applies each disability to what's left of your whole person after the previous disabilities are applied. The result is always less than the sum of your individual ratings.
The Whole Person Method — Step by Step
Let's say you have three conditions rated at 50%, 30%, and 20%. Here's exactly how the VA calculates your combined rating:
Example: 50% + 30% + 20%
Step 1: Start with 100% (you as a whole person).
Apply the highest rating first: 50% of 100% = 50 points disabled.
Remaining: 100 − 50 = 50% still whole
Step 2: Apply the next rating to what remains.
30% of 50% remaining = 15 points disabled.
Remaining: 50 − 15 = 35% still whole
Step 3: Apply the last rating to what remains.
20% of 35% remaining = 7 points disabled.
Remaining: 35 − 7 = 28% still whole
Raw combined: 100 − 28 = 72% disabled
Rounded to nearest 10%: 70% combined rating
So three ratings totaling 100% in simple addition result in only a 70% combined rating using VA math. This surprises nearly every veteran the first time they see it.
More Real-World Examples
| Individual Ratings | Simple Sum | VA Math Result | Rounded Rating | Monthly Pay |
|---|---|---|---|---|
| 70% + 30% | 100% | 79% | 80% | $2,102.15 |
| 50% + 50% | 100% | 75% | 80% | $2,102.15 |
| 60% + 40% | 100% | 76% | 80% | $2,102.15 |
| 70% + 50% + 10% | 130% | 86.5% | 90% | $2,362.30 |
| 80% + 40% + 20% | 140% | 90.4% | 90% | $2,362.30 |
| 70% + 50% + 30% + 10% | 160% | 90.3% | 90% | $2,362.30 |
The Rounding Rule
After the VA calculates your raw combined disability percentage, it rounds to the nearest 10%:
- Raw 1%–4% → rounds down to 0%
- Raw 5%–14% → rounds to 10%
- Raw 15%–24% → rounds to 20%
- Raw 45%–54% → rounds to 50%
- Raw 95%–100% → rounds to 100%
This rounding can work in your favor or against you. A raw combined of 85% rounds up to 90% — a meaningful difference in pay. A raw combined of 84% rounds down to 80%. This is why getting that extra condition rated can sometimes be worth more than you'd expect.
If your raw combined is 85% or higher, adding even a small additional condition can tip the rounding up to 90%. If you're at 90% raw, you need to reach 95% to round up to 100%. Use our Combined Rating Calculator to see exactly where you stand and how close you are to the next tier.
Why Adding More Conditions Always Helps
Even though VA math means your rating grows slower than a simple addition, adding more service-connected conditions almost always increases your monthly pay. Here's why it's always worth claiming everything:
- Each additional condition increases your raw combined percentage
- A small bump can tip the rounding to the next tier, resulting in a significant pay jump
- Even conditions rated at 0% establish service connection, which matters for future rating increases if the condition worsens
- Service-connected conditions (even 0%) may qualify you for VA healthcare for that specific condition
Bilateral Factor — The Exception That Helps You
There is one important exception to standard VA math that actually works in veterans' favor: the bilateral factor. If you have ratable disabilities affecting both arms, both legs, or paired skeletal muscles, the VA adds a 10% bonus to the combined value of those bilateral disabilities before combining with your other ratings.
Bilateral Factor Example
Say you have a 20% rating on your right knee and a 10% rating on your left knee.
Combined bilateral value: 28% (using VA math on just those two).
Bilateral factor: add 10% of 28% = 2.8 points.
Adjusted bilateral value: 28 + 2.8 = 30.8% before combining with other conditions.
This bonus can meaningfully increase your overall combined rating, especially for veterans with multiple joint injuries.
How to Use This Knowledge
Understanding VA math helps you make strategic decisions about your claims:
- File all conditions: Don't self-filter. Every condition matters, even small ones near the rounding thresholds.
- Check where you are: Use our Combined Rating Calculator to see your exact raw number and how close you are to rounding up.
- Prioritize secondary conditions: If you're at 82% raw, a new 10% secondary condition might push you to 90% on the rounding.
- Understand TDIU threshold: If your combined reaches 70% with one condition at 40%+, TDIU eligibility opens up.
Try the Combined Rating Calculator
Enter your individual ratings and see your exact VA math result — including how close you are to the next pay tier.
Calculate My Combined Rating →Bottom Line
VA math is frustrating, but understanding it gives you a strategic advantage. The system is not designed to give you 100% just because your conditions add up to 100% on paper. But it does reward veterans who file every qualifying condition, understand the rounding thresholds, and know when they're close to a higher tier. Use that knowledge.