VA Combined Ratings Calculator: How the VA Math Really Works

If you have multiple service-connected disabilities, you've probably tried to calculate your combined VA rating by adding the percentages together. And you've probably been confused when the VA gave you a different number than you expected.

Here's the thing: The VA doesn't use simple addition. They use something called "VA math" - a unique calculation method that often results in a lower combined rating than you'd get by just adding percentages.

This guide explains exactly how VA combined ratings work, with step-by-step examples and a free calculator to help you estimate your rating.

Why Doesn't the VA Just Add Percentages?

The VA's system is based on the concept of remaining efficiency. The idea is that each disability reduces your remaining functional capacity, not your total capacity.

Think of it this way: You start at 100% efficient (fully functional). If you have a 50% disability, the VA considers you 50% efficient - you've lost half your capacity. If you then have a second 30% disability, that 30% doesn't apply to the full 100%. Instead, it applies to your remaining 50% efficiency.

This prevents the combined rating from exceeding 100% when veterans have multiple conditions. If the VA simply added percentages, someone with four 30% ratings would be 120% disabled - which doesn't make sense.

The VA Combined Ratings Formula

Here's the step-by-step process the VA uses:

1. List all your disability ratings from highest to lowest
2. Start with the highest rating
3. Calculate the remaining efficiency (100% minus the current rating)
4. Multiply the next rating by the remaining efficiency
5. Add that result to your current rating
6. Repeat steps 3-5 for each additional rating
7. Round the final result to the nearest 10%

Let's break this down with real examples.

Example 1: Two Conditions

Step 1: Start with the highest rating: 30%

Step 2: Calculate remaining efficiency: 100% - 30% = 70%

Step 3: Multiply the next rating by remaining efficiency: 10% × 70% = 7%

Step 4: Add to current rating: 30% + 7% = 37%

Step 5: Round to nearest 10%: 37% rounds to 40%

Final Combined Rating: 40%

Note: If you had simply added 30% + 10%, you'd expect 40% - and in this case, you'd be right. But that's just luck due to rounding. Let's look at a more dramatic example.

Example 2: Three Conditions

Step 1: Start with the highest rating: 50%

Step 2: Remaining efficiency: 100% - 50% = 50%

Step 3: Apply next rating (40%): 40% × 50% = 20%

Step 4: Add: 50% + 20% = 70%

Step 5: Remaining efficiency: 100% - 70% = 30%

Step 6: Apply final rating (20%): 20% × 30% = 6%

Step 7: Add: 70% + 6% = 76%

Step 8: Round to nearest 10%: 76% rounds to 80%

Final Combined Rating: 80%

If you had simply added 50% + 40% + 20%, you'd expect 110% - which is impossible. VA math gives you 80%, which is more realistic but still accounts for all three conditions.

The Rounding Rules

The VA rounds your final combined rating to the nearest 10%. But the rounding is done mathematically:

• 0-4 rounds down: 74% becomes 70%
• 5-9 rounds up: 75% becomes 80%

This is where things get frustrating for many veterans. If your combined rating calculates to 94%, you're at 90% for compensation purposes. You're just 1% away from the 100% tier, which pays significantly more.

That's why it's so important to claim every service-connected condition - even "small" 10% ratings can push you over the rounding threshold.

The Bilateral Factor

If you have disabilities affecting both sides of your body (bilateral disabilities), the VA applies an additional calculation before combining with other ratings.

How the Bilateral Factor Works

1. Add the ratings for both bilateral conditions
2. Multiply the sum by 10% (this is the bilateral factor)
3. Add that bonus to the sum
4. Treat this total as a single rating and combine with others using VA math

The bilateral factor recognizes that having disabilities on both sides of your body is more debilitating than having them on one side. It's a small boost, but it can help you reach the next rounding threshold.

Real-World Example: Multiple Conditions

Let's put it all together with a realistic scenario:

Step 1: Apply bilateral factor to knees

• Sum: 20% + 10% = 30%
• Bilateral bonus: 30% × 10% = 3%
• Total: 33%

Step 2: List all ratings from highest to lowest

• PTSD: 70%
• Back: 40%
• Knees (bilateral): 33%
• Sleep apnea: 30%
• Tinnitus: 10%

Step 3: Combine using VA math

• Start: 70%
• Remaining: 30% → 40% of 30% = 12% → Total: 82%
• Remaining: 18% → 33% of 18% = 6% → Total: 88%
• Remaining: 12% → 30% of 12% = 3.6% → Total: 91.6%
• Remaining: 8.4% → 10% of 8.4% = 0.84% → Total: 92.44%

Step 4: Round: 92.44% rounds down to 90%

Final Combined Rating: 90%

This veteran receives 90% disability compensation, even though their individual ratings add up to 210% with simple math.

Tips for Maximizing Your Combined Rating

• Claim everything: Don't ignore "minor" conditions. A 10% rating could push you from 84% to 85%, which rounds to 90% instead of 80%.
• File for secondary conditions: If one disability caused another (e.g., knee injury led to hip pain), file the secondary condition separately.
• Understand bilateral disabilities: Make sure the VA applies the bilateral factor if you have conditions affecting both sides of your body.
• Keep detailed records: The higher your combined rating, the more monthly compensation you receive. Accurate documentation matters.

Final Thoughts

VA math isn't intuitive, but it makes sense once you understand the efficiency-based system. The key takeaway: Don't try to guess your combined rating by adding percentages. Use a calculator or do the math step-by-step using the VA's formula.

And remember - every percentage point matters. Don't leave benefits on the table by failing to claim conditions or secondary disabilities. Fight for every point you're entitled to, because those percentages translate to real compensation that can make a difference in your life.

Disclaimer: This article provides general information and should not be considered legal or medical advice. Always consult official VA resources and a Veterans Service Officer (VSO) for guidance specific to your situation.