How VA Disability Ratings Are Calculated (With Examples)

Understanding how the VA calculates disability ratings helps veterans know what to expect from their claim and whether their combined rating accurately reflects their service-connected conditions. The VA does not simply add percentages together. It uses a specific method often called “VA math” to combine ratings while accounting for the “whole person” efficiency concept.

This article explains the process in plain English, including the bilateral factor and Total Disability based on Individual Unemployability (TDIU), with clear examples based on 2026 rates and rules.

The basic rating process

The VA assigns each service-connected condition a rating from 0 to 100 percent in increments of 10 percent, based on severity and diagnostic code criteria in the VA Schedule for Rating Disabilities (38 CFR Part 4).

When a veteran has multiple conditions, the VA combines them using a combined ratings table rather than simple addition. The idea is that each additional disability affects the remaining “efficiency” of the whole person.

How VA math works step by step

1. List all individual ratings in descending order (highest to lowest).
2. Start with the highest rating.
3. Take the next rating as a percentage of the remaining efficiency (100 minus the current combined percentage).
4. Add that value to the running total.
5. Repeat for each additional rating.
6. Round the final combined value to the nearest 10 percent.

Example 1: Simple combination

A veteran has two conditions rated at 50 percent and 30 percent.

• Start with 50 percent. Remaining efficiency: 50 percent.
• 30 percent of 50 percent = 15 percent.
• Combined: 50 + 15 = 65 percent, rounded to 70 percent.

Example 2: More conditions

Ratings of 40 percent, 30 percent, and 20 percent.

• Start with 40 percent. Remaining: 60 percent.
• 30 percent of 60 percent = 18 percent. Combined so far: 58 percent.
• 20 percent of remaining 42 percent ≈ 8.4 percent.
• Total before rounding: approximately 66.4 percent, rounded to 70 percent.

The bilateral factor

When disabilities affect paired body parts (both arms, both legs, or paired skeletal muscles), the VA applies a bilateral factor. First combine the ratings for the paired extremities using VA math, then add 10 percent of that combined value before combining with other ratings. This extra factor recognizes the additional impact of symmetric impairments.

Example with bilateral factor

A veteran has 30 percent left knee and 20 percent right knee (bilateral lower extremities).

• Combine 30 percent and 20 percent first: 44 percent (before rounding).
• Bilateral factor: 10 percent of 44 percent = 4.4 percent.
• Adjusted bilateral rating: 48.4 percent.
• Then combine this with any other ratings.

Total Disability based on Individual Unemployability (TDIU)

If service-connected conditions prevent you from maintaining substantially gainful employment, you may qualify for TDIU. This pays at the 100 percent rate even if your combined schedular rating is lower. Common thresholds: one condition rated at least 60 percent, or combined rating of 70 percent with one condition at least 40 percent. You can also qualify on an extraschedular basis.

2026 compensation context

Monthly compensation amounts for 2026 reflect the latest cost-of-living adjustment. A 100 percent rating provides significantly higher monthly payment than lower combined ratings. Accurate calculation matters for both compensation and access to additional benefits.

Ready to Use These Tools

All 14 VA tools on Bill Advantage are permanently free for all users with no monthly limits. Use the PACT Act Benefits Screener and VA Benefits Navigator to get started.

---

Bill Advantage is a document literacy tool. Nothing in this article constitutes legal or medical advice.