How VA Combined Ratings Are Calculated Step by Step

Every veteran with more than one service-connected condition needs to understand this process. The VA does not add your disability percentages together. It uses a specific formula that applies each rating sequentially to a shrinking remainder, which is why your combined rating is almost always lower than you expect. This page walks through every step of that formula, shows exactly how the VA reaches a final number, and explains what happens when bilateral conditions and rounding are involved.

The Foundation: What the VA Is Actually Measuring

Before you can understand the steps, you need to understand what the VA is trying to measure. The VA's position is that a person cannot be more than 100% disabled. Your body starts the calculation as a whole: 100% efficient, 0% disabled.

Each service-connected disability reduces that efficiency. But critically, the VA does not measure each reduction against your original 100%. It measures each reduction against whatever efficiency is left after the previous condition was applied.

This is the core of the whole person concept, and it is the reason VA math produces results that confuse every veteran who encounters it for the first time.

The Six Steps the VA Uses to Calculate Your Combined Rating

Here is the exact process the VA follows every time it calculates a combined rating. You can use these same steps to verify your own rating decision or estimate what a new claim would add to your existing combined rating.

Step 1: List all service-connected disabilities

Write down every condition the VA has service-connected for you, along with its individual percentage rating. Only service-connected conditions are included in the combined rating. Non-service-connected conditions do not count.

Step 2: Sort ratings from highest to lowest

Arrange your ratings in descending order: highest percentage first, lowest last. This order matters. The VA always applies the most severe condition to the full remaining efficiency first.

Exception: If you have bilateral conditions, disabilities on both sides of a paired body part, those are handled separately first.

Step 3: Apply the highest rating to 100%

Start with 100% whole person efficiency. Multiply your highest rating by 100% to calculate how much disability it represents. Subtract that from 100% to find your remaining efficiency.

Formula: Remaining efficiency = 100 - (highest rating x 100)

Example: Highest rating is 50%. 50% x 100 = 50 points of disability. Remaining efficiency = 100 - 50 = 50%.

Step 4: Apply each subsequent rating to the remaining efficiency

Take your next rating and multiply it by your current remaining efficiency, not the original 100%. Subtract the result from your remaining efficiency. Repeat this step for every rating, working from highest to lowest.

Formula: New remaining = Previous remaining - (next rating x previous remaining)

Example: Next rating is 30%. Remaining efficiency is 50%. 30% x 50 = 15 points of disability. New remaining = 50 - 15 = 35%.

Step 5: Apply the bilateral factor if applicable

If you have service-connected disabilities affecting both sides of a paired body part, such as both knees, both shoulders, both hands, or both ankles, the bilateral factor applies before those conditions are entered into the main calculation.

1. Combine the bilateral conditions using the standard whole person formula.
2. Calculate 10% of that combined bilateral value.
3. Add that 10% to the combined bilateral value.
4. Treat the result as a single rating and enter it into the main calculation in its correct position by size.

Example: Left knee 30%, right knee 20%. These combine to 44%. The bilateral factor adds 10% of 44 = 4.4 points. Bilateral entry into main calculation: 48.4%.

Step 6: Calculate combined disability and round to nearest 10%

Once all ratings have been applied, your combined disability is 100 minus your final remaining efficiency. This is your unrounded combined value.

• Endings of 1% to 4% round down.
• Endings of 5% to 9% round up.

This rounded result is your official combined VA disability rating. The VA does not round between steps. Rounding happens exactly once, at the very end.

Full Worked Example: Three Conditions Through Every Step

Here is a complete calculation for a veteran with three service-connected conditions: PTSD at 70%, lumbar spine/back pain at 30%, and tinnitus at 10%.

Individual ratings total 110%. Combined result using VA math: 80%. That 30-point gap is why understanding the formula matters before you file.

Worked Example With Bilateral Factor: Back, Both Knees, Tinnitus

This example includes bilateral conditions, a situation many veterans face when both knees or both shoulders are service-connected. The bilateral conditions must be handled before entering the main calculation.

Three Calculation Mistakes That Lead Veterans to the Wrong Number

Mistake 1: Rounding between steps

Some veterans round their remaining efficiency after each step. The VA does not do this. Your exact decimal value carries through every step. Rounding only at the end is what produces accurate results.

Mistake 2: Applying bilateral ratings individually into the main calculation

Veterans who have bilateral conditions sometimes enter each bilateral condition separately into the main formula without first applying the bilateral factor. Bilateral conditions must be combined together first, the 10% boost applied, and the resulting single value entered into the main calculation.

Mistake 3: Including non-service-connected conditions

Only conditions that have been formally service-connected by the VA count in the combined rating calculation. Conditions you have that the VA has not service-connected do not affect your combined rating.

How to Use This Formula to Plan Your Next Claim

Understanding the calculation steps gives you practical information you can act on before you file a new claim or an appeal.

First, calculate your current unrounded combined value using the steps above or our free VA combined rating calculator. Knowing your exact unrounded value tells you how many points you are away from the next rounding threshold.

If your unrounded combined is 74%, you are 1 point away from 75%, which rounds to 80% instead of 70%. A new condition that adds even 3 to 4 points of disability to your combined value would push you over that threshold and increase your monthly pay significantly.

Secondary conditions are often the most efficient way to add those points because they do not require a direct nexus to military service, only a connection to a condition you are already rated for.

Frequently Asked Questions

How does the VA calculate combined disability ratings?

The VA sorts all ratings from highest to lowest, then applies each rating to the remaining healthy percentage of the veteran's body, not to the original 100%. This is called the whole person method, defined in 38 CFR § 4.25. The final combined value is then rounded to the nearest 10%.

What is the first step in calculating a VA combined rating?

The first step is to list all service-connected disability ratings and sort them from highest to lowest. The VA always applies the most severe condition first.

Does the VA round between calculation steps?

No. The VA does not round between steps. Rounding only happens once, at the very end of the entire calculation.

What is the bilateral factor in VA combined rating calculations?

The bilateral factor is an additional 10% boost applied when a veteran has service-connected disabilities affecting both sides of a paired body part.

Can I calculate my own VA combined rating?

Yes. Follow the six steps on this page, or use our free VA combined rating calculator to get the same result instantly.