What Is VA Math? How Combined Disability Ratings Actually Work

You have a 50% rating for PTSD. A 30% rating for a back injury. A 10% rating for tinnitus.

So your combined disability rating should be 90%, right?

Wrong.

According to the VA, you are rated at 65% — which rounds down to 60%.

Welcome to VA math.

If that feels like you just got cheated out of money you earned, you are not alone. VA math confuses and frustrates veterans every single day. But once you understand exactly how it works, you can make smarter decisions about your claims — and figure out whether you are being rated accurately.

This guide breaks down the VA’s combined rating formula step by step, with real examples, so there are no more surprises.

Why the VA Does Not Just Add Up Your Percentages

The VA uses a system called the whole person method to calculate combined disability ratings. The core idea behind it is this: the VA treats your body as a single unit representing 100% capacity. Each disability reduces that capacity — but it can only reduce what remains, not the whole thing again.

Think of it like stacking discounts on a purchase. A 50% discount followed by a 30% discount does not give you 80% off. It gives you 65% off — because the second discount applies to the already-reduced price.

The VA applies the same logic to your body.

This method was not designed to punish veterans. It was designed on the theory that you cannot be more than 100% disabled. But in practice, it consistently produces combined ratings significantly lower than veterans expect — and lower than many arguably deserve.

How VA Math Works — Step by Step

Here is the exact formula the VA uses:

Step 1: List all your service-connected disabilities from highest to lowest percentage.

Step 2: Start with 100% — your “whole person.”

Step 3: Apply your highest-rated disability first. Subtract it from 100%.

Step 4: Apply your next disability to the remaining percentage — not to 100%.

Step 5: Repeat for each additional condition.

Step 6: Add all the disability values together to get your combined raw percentage.

Step 7: Round to the nearest 10% increment. If the result ends in 1–4, round down. If it ends in 5–9, round up.

VA Math Example — Three Conditions

Let’s walk through a real example with three conditions:

• PTSD: 50%
• Back injury: 30%
• Tinnitus: 10%

Step 1: Start with 100% whole person.

Step 2: Apply 50% PTSD.

• 50% of 100% = 50 points of disability
• Remaining whole person: 100 − 50 = 50% remaining

Step 3: Apply 30% back injury to the remaining 50%.

• 30% of 50% = 15 points of disability
• Remaining whole person: 50 − 15 = 35% remaining

Step 4: Apply 10% tinnitus to the remaining 35%.

• 10% of 35% = 3.5 points of disability
• Remaining whole person: 35 − 3.5 = 31.5% remaining

Step 5: Add all disability points:

• 50 + 15 + 3.5 = 68.5% combined

Step 6: Round to the nearest 10%.

• 68.5% rounds up to 70%

So a veteran with a 50%, 30%, and 10% rating ends up at 70% combined — not 90%.

That is a difference of 20 percentage points, which in 2026 translates to roughly $600 less per month in tax-free compensation.

VA Math Example — Two Conditions

Let’s try a simpler example that surprises a lot of veterans:

• Knee injury: 40%
• Sleep apnea: 50%

Step 1: Start with 100% whole person.

Step 2: Apply the higher rating first — 50% sleep apnea.

• 50% of 100% = 50 points
• Remaining: 50% remaining

Step 3: Apply 40% knee injury to remaining 50%.

• 40% of 50% = 20 points
• Remaining: 30% remaining

Step 4: Add disability points:

• 50 + 20 = 70% combined

Step 5: Round to nearest 10%.

• 70% stays at 70%

A veteran with a 50% and 40% rating ends up at 70% combined — not 90%.

VA Math Quick Reference Table

Here is a reference for common two-condition combinations so you can quickly see what to expect:

Notice how two conditions that seem like they should add up to 100% almost never do. This is exactly why veterans consistently feel their combined ratings are lower than they should be — because mathematically, they are.

VA math is the formula — but the formula only works correctly if all your conditions are on the table.

If you have service-connected conditions you never filed for, the VA cannot include them in the calculation. If your existing ratings are lower than your symptoms warrant, the formula produces a lower result. If secondary conditions — like back pain caused by a knee injury, or sleep apnea caused by PTSD — were never claimed, they are not part of the math.

The formula itself is not the only problem. What goes into the formula matters just as much.

This is why veterans with what appears to be a straightforward collection of conditions still end up underrated — the inputs are incomplete.

If you want to understand whether your current combined rating accurately reflects your conditions, the Free Disability Review at VA.org walks through your full picture and helps identify what may be missing.

The Bottom Line

VA math is real, it is not intuitive, and it almost always produces a lower combined rating than you would expect by simply adding up your percentages.

Understanding how it works puts you in a better position to:

• Know whether your current rating makes sense
• Identify which additional conditions are worth filing for
• Understand how close you are to the next rating tier
• Make informed decisions about rating increase claims

The first step is knowing your numbers.

👉 Estimate Your Combined Rating — Free at VA.org

If you have questions about your specific situation, AI Joe — VA.org’s free 24/7 veteran specialist chatbot — can walk you through your options in plain language, any time of day.

VA.org is an independent, privately owned platform. We are not affiliated with or endorsed by the U.S. Department of Veterans Affairs. All tools on VA.org are 100% free.

Benefit amounts and rating examples shown are approximate figures for 2026. Actual combined ratings may vary based on bilateral factors, special monthly compensation, and other VA-specific rules. Always verify your rating at VA.gov or with a VA-accredited claims agent.