How combined ratings are calculated

This is one of the most misunderstood parts of VA disability. Most veterans assume that a 30% rating plus a 20% rating equals a 50% combined rating. That is wrong. VA does not add ratings. It uses what is called the “whole person” formula, defined in 38 CFR § 4.25.

Key concept

VA does not add disability ratings. It applies each rating to the percentage of you that is still considered healthy. Each new rating takes a bite out of what is left, not out of the original 100%.

The whole person formula — step by step

Start with a healthy person — 100% efficient.

1. Apply your highest disability rating first. Subtract that percentage from 100% to find your “efficiency remaining.”
2. Apply the next-highest rating to whatever efficiency is remaining.
3. Continue down the list, each rating applied to what’s left after the prior ones.
4. Subtract the final remaining efficiency from 100% to find your combined disability percentage.
5. Round to the nearest 10. (5 rounds up. 4 rounds down.)

Worked example: PTSD 70% + Sleep Apnea 50% + Migraines 30% + Tinnitus 10% + ED 0%

Starting at 100% efficient:

• PTSD 70% applied to 100% → 70% disabled, 30% efficient remaining
• Sleep Apnea 50% applied to remaining 30% → 15% additional disability → 15% efficient remaining
• Migraines 30% applied to remaining 15% → 4.5% additional disability → 10.5% efficient remaining
• Tinnitus 10% applied to remaining 10.5% → 1.05% additional disability
• ED 0% adds nothing to the combined rating (but qualifies you for SMC-K — see SMC ladder)
• Combined: 90.55%, rounded to 90%

The same person under straight addition would have appeared to be 160% disabled. The whole-person formula caps the total at 100%.

The bilateral factor (38 CFR § 4.26)

For disabilities affecting paired body parts (both arms, both legs, both knees, both ankles, both eyes, etc.), VA adds an extra 10% on top of the combined rating of the bilateral disabilities before merging into the overall combined rating. This is one of the few true “boosts” in the system.

Example: right knee 20%, left knee 10%. Combined: 28%. Bilateral factor: 10% of 28% = 2.8%, added back. 28% + 2.8% = 30.8%. Rounds to 30%. That 30% enters the overall combined rating calculation.

Strategy

Always check whether a paired-limb condition could be filed bilaterally. If you have right knee pain but also some left knee pain, do not just claim the worse knee. Claim both. Even a 0% rating on the second knee triggers the bilateral factor.

Use the calculator

Do not try to do this math in your head. Use the Combined Rating Calculator to model your numbers before and after each potential new claim. Sometimes a 10% additional rating doesn’t move the needle. Sometimes a 0% rating triggers SMC and is worth filing anyway.

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