How does the bilateral factor calculation work?

Step 1: Add the bilateral condition ratings together (e.g., right knee 10% + left knee 10% = 20%). Step 2: Calculate 10% of that combined value (10% × 20% = 2%). Step 3: Add the bilateral factor to the combined value (20% + 2% = 22%). Step 4: Use this 22% as the starting point in the combined ratings formula with your other disabilities. Without the bilateral factor, the two 10% ratings would combine to approximately 19% — the bilateral factor adds 3 percentage points, which can be enough to push you into the next rating tier.

Can I file a claim if the VA didn't apply the bilateral factor?

Yes. If the VA failed to apply the bilateral factor when it should have, or applied it incorrectly, you can file a Supplemental Claim citing 38 CFR § 4.26 as the basis for a corrected combined rating calculation. Request your C-file to see the actual rating worksheet, compare the math, and if the bilateral factor was omitted, a supplemental claim or Notice of Disagreement (NOD) is the appropriate route to correction.

Does bilateral neuropathy qualify for the bilateral factor?

Yes, peripheral neuropathy affecting paired extremities qualifies for the bilateral factor. For example, a veteran with service-connected neuropathy in both hands, both feet, or both lower extremities can apply the bilateral factor to those paired ratings. A veteran with neuropathy in all four limbs (both hands AND both feet) would apply the bilateral factor separately to the arm pair and the leg pair. The bilateral factor can be applied to multiple separate bilateral pairs in the same overall combined calculation.

Rating Math

VA Bilateral Factor Explained: Calculator, Examples & SMC Impact (2026)

Q: What conditions qualify for the bilateral factor?

Qualifying conditions include: both knees, both hips, both ankles/feet, both shoulders, both elbows/wrists/hands, both ears (hearing loss), both eyes, both thighs (femur), and bilateral neuropathy affecting paired limbs. The conditions on each side do NOT need to be identical or equally rated. Conditions that do NOT qualify include: internal organs, mental health conditions (PTSD, depression), tinnitus (rated as single condition under DC 6260), and single-limb conditions.

Q: Does bilateral hearing loss qualify for the bilateral factor?

Yes, bilateral hearing loss (rated under DC 6100) qualifies for the bilateral factor under 38 CFR § 4.26. However, tinnitus does NOT qualify, even if bilateral, because tinnitus is rated as a single condition under DC 6260 regardless of which ear(s) are affected. Many veterans have both bilateral hearing loss AND tinnitus — the bilateral factor applies only to the hearing loss ratings, not to the tinnitus.

Q: Does the bilateral factor affect SMC eligibility?

The bilateral factor affects your combined disability rating, which in turn can affect SMC eligibility. Veterans at 100% combined rating with additional disabilities may qualify for SMC(s) — Special Monthly Compensation housebound — or SMC(l) through SMC(o) for specific anatomical losses or loss of use. A higher combined rating driven by the bilateral factor can also make it easier to reach the 60% plus 60% threshold needed for SMC(s). If you're near an SMC threshold, have a VA attorney or accredited claims agent review your bilateral conditions.

Marcus J. Webb Veterans Benefits Researcher

Reviewed against 38 CFR · Updated June 2026

The VA's combined rating system is already confusing — but buried inside it is a bonus most veterans never receive. If you have ratable conditions on both sides of your body — both knees, both ears, both shoulders, both feet — the bilateral factor under 38 CFR § 4.26 increases your combined rating before it's finalized. It's not always huge. But it's money you're legally entitled to, and if the VA isn't applying it correctly, your rating is wrong.

📋 In This Guide

What Is the Bilateral Factor?
The Math — Step by Step
Interactive Bilateral Factor Calculator
What Conditions Qualify
What Does NOT Qualify
Real-World Examples (Knees, Ears, Neuropathy)
How Bilateral Factor Stacks With SMC
How to Check If the VA Applied It Correctly
Printable Worksheet
Frequently Asked Questions

What Is the Bilateral Factor?

The bilateral factor is a rating adjustment under 38 CFR § 4.26 that applies when a veteran has ratable disabilities affecting paired extremities or organs — both arms, both legs, both hands, both feet, both knees, both hips, both ears, or both eyes. The regulation recognizes that losing function on both sides of the body has a compounding effect greater than what simple combined rating arithmetic would produce.

The basic mechanism: before the standard combined ratings formula is applied to bilateral conditions, the ratings for those paired conditions are added together and then increased by 10%. That adjusted number then enters the combined ratings calculation alongside all other disabilities.

The bilateral factor is not discretionary. Under 38 CFR § 4.26, the VA is required to apply it whenever qualifying bilateral conditions exist. If it wasn't applied to your rating, that's an error — and it's correctable.

The Math — Step by Step

Let's start with the simplest example: both knees rated at 10%.

Example: Right knee 10% + Left knee 10% Step 1 — Add bilateral ratings together: 10% + 10% = 20% Step 2 — Calculate the bilateral factor (10% of combined): 10% \times 20% = 2% Step 3 — Add bilateral factor to combined value: 20% + 2% = 22% (bilateral combined value) Step 4 — Run 22% through standard combined formula with other disabilities (instead of running 10% and 10% separately) Without bilateral factor: two 10% ratings \to ~19% combined With bilateral factor: 22% \to more significant when stacked with other conditions

📊 Bigger Impact at Higher Ratings

The bilateral factor has a larger absolute effect at higher individual ratings. Two 20% knee ratings become 44% with bilateral factor (vs. 36% without). Two 30% shoulder ratings become 66% bilateral (vs. 51% without). The higher the individual ratings, the more meaningful the bump — and the more likely it is to push you into the next combined rating tier.

Interactive Bilateral Factor Calculator

🧮 Bilateral Factor Calculator

Enter the ratings for your bilateral pair (left and right side of the same body part). The calculator will show you the bilateral-adjusted combined value to use in your overall combined rating calculation.

Left side rating (%):

Right side rating (%):

Results will appear here after you enter both ratings and click Calculate.

How to use this calculator: Enter the VA-assigned rating for each side of the same bilateral condition. The result gives you the "bilateral adjusted value" — the number you'll use when combining this condition pair with your other conditions in the overall combined rating formula.

What Conditions Qualify for the Bilateral Factor

Under 38 CFR § 4.26, the bilateral factor applies to conditions affecting paired extremities and organs. Here are the most common qualifying combinations:

🦴 Both Knees

Extremely common among veterans. Right and left knee at any ratings qualify — they don't need to be equal.

🦴 Both Hips

Bilateral hip conditions — arthritis, avascular necrosis, hip replacement residuals — all qualify.

🦴 Both Ankles / Feet

Plantar fasciitis, pes planus, ankle instability, or fracture residuals affecting both feet.

🦴 Both Shoulders

Rotator cuff tears, impingement syndrome, or post-surgical residuals on both shoulders.

📻 Both Ears (Hearing Loss)

The most common bilateral condition in the VA system. Bilateral hearing loss under DC 6100 qualifies.

👀 Both Eyes

Visual acuity conditions, glaucoma, or other ratable visual conditions affecting both eyes.

💪 Both Elbows / Wrists / Hands

Carpal tunnel, epicondylitis, or joint conditions on both upper extremities.

⚡ Bilateral Neuropathy

Peripheral neuropathy in both hands, both feet, or both lower extremities from diabetes, Agent Orange, or other causes.

Important rule: The conditions on each side do NOT need to be identical or cause the same disability. A veteran with a right knee at 10% (limited flexion) and a left knee at 20% (instability plus limited flexion) still qualifies for the bilateral factor — both knees are affected, and the law doesn't require symmetry.

Multiple Bilateral Pairs

A veteran can have multiple bilateral pairs in a single combined rating calculation. For example:

Both knees (bilateral pair 1) → apply bilateral factor to get adjusted knee value
Both ears/hearing loss (bilateral pair 2) → apply bilateral factor to get adjusted hearing value
Both ankles (bilateral pair 3) → apply bilateral factor to get adjusted ankle value

Each bilateral pair is adjusted separately first, then all the adjusted values plus any non-bilateral conditions are combined using the standard combined ratings formula.

What Does NOT Qualify

Single-limb conditions — one knee, one shoulder, one ear (only) — no bilateral pair means no bilateral factor
Internal organs — bilateral kidney disease, bilateral lung conditions — paired but not "extremities" under § 4.26
Mental health conditions — PTSD, depression, anxiety — these are not extremity conditions
Tinnitus — even when affecting both ears, tinnitus is rated as a single condition under DC 6260; it does not receive a separate bilateral adjustment
Migraine headaches — even if bilateral by nature
Skin conditions — rash, dermatitis affecting both arms — generally not subject to the bilateral factor

⚠ Tinnitus vs. Hearing Loss

Many veterans have BOTH bilateral hearing loss AND tinnitus. The bilateral factor applies to the hearing loss ratings (DC 6100) — but NOT to tinnitus (DC 6260). These are treated as separate conditions. Your hearing loss pair gets the bilateral adjustment; your tinnitus is rated at its standalone percentage (usually 10%) and combined with everything else separately.

Real-World Examples

Example 1: Bilateral Knees + PTSD

Veteran has: Right knee 20%, Left knee 10%, PTSD 50%.

Step 1 — Bilateral factor for knees: 20% + 10% = 30% Bilateral factor: 10% \times 30% = 3% Adjusted bilateral knee value: 33% Step 2 — Combine 33% (knees) with 50% (PTSD): 50% + (33% \times 50% efficiency remaining) = 50% + 16.5% = 66.5% Rounded: 67% \to rounds to 70% Without bilateral factor: Knees (20% + 10%): 20% + (10% \times 80%) = 28% 28% + PTSD 50%: 50% + (28% \times 50%) = 64% \to rounds to 60% Difference: 70% vs. 60% — a full rating tier Annual dollar difference: ~$4,300/year in additional tax-free VA compensation

Example 2: Bilateral Hearing Loss (Both Ears)

Veteran has: Right ear hearing loss 10%, Left ear hearing loss 20%, Tinnitus 10%, Knee 10%.

Step 1 — Bilateral factor for hearing loss only (NOT tinnitus): 10% + 20% = 30% Bilateral factor: 3% Adjusted hearing value: 33% Step 2 — Combine all conditions (33% hearing + 10% tinnitus + 10% knee): 33% + (10% \times 67%) + (10% \times \sim60%) = 33% + 6.7% + 6% \approx 46% Rounded: 50% Without bilateral factor: Hearing combined without BF: ~28% All combined: ~40% \to rounds to 40% Difference: 50% vs. 40% — another full tier Monthly difference 2026: $1,395.93 (50%) vs. $774.16 (40%) = +$621/month

Example 3: Peripheral Neuropathy — All Four Limbs

Veterans with diabetic neuropathy or neuropathy from Agent Orange exposure often have bilateral conditions in BOTH their upper and lower extremities. This creates two separate bilateral pairs.

Veteran has: Both hands neuropathy (right 10%, left 10%) + Both feet neuropathy (right 20%, left 20%) Bilateral pair 1 — Hands: 10% + 10% = 20% + 2% BF = 22% Bilateral pair 2 — Feet: 20% + 20% = 40% + 4% BF = 44% Combine 44% (feet) with 22% (hands): 44% + (22% \times 56%) = 44% + 12.3% = 56.3% \to 56% \to rounds to 60% Without bilateral factor: Feet combined: ~36%. Hands combined: ~19% All combined: 36% + (19% \times 64%) \approx 48% \to 50% Bilateral factor properly applied across 4 limbs: 60% vs. 50% without

How Bilateral Factor Stacks With SMC

The bilateral factor directly affects your combined disability rating, which in turn affects Special Monthly Compensation (SMC) eligibility thresholds. Here's why this matters:

SMC(s) — Housebound Status

SMC(s) is available to veterans who are rated 100% combined AND have an additional separate service-connected disability rated 60% or more. The bilateral factor can be the difference between having a 50% separate condition that "counts" versus reaching that critical 60% threshold. More importantly, if your bilateral conditions are helping push your overall combined to 100%, SMC(s) eligibility becomes relevant.

SMC Level	Basic Threshold	How Bilateral Factor Helps
SMC(s) Housebound	100% combined + additional 60% SC condition	BF can push combined to 100% or push secondary condition to 60%
SMC(l) through (o)	Anatomical loss or loss of use of limb/organ	BF helps reach 100% SC threshold often required alongside SMC awards
A&A (Aid & Attendance)	Need for regular aid and attendance of another person	Rating level affects A&A rate; higher combined = higher base SMC before A&A addition

The 100% Combined Rating Threshold

Veterans who are near 95% combined with bilateral conditions should always verify that the bilateral factor was applied. A missed bilateral factor that adds 3–5 percentage points could be the difference between 95% (rounds to 100% VA schedular) and a correctly calculated 100% — which then opens the door to SMC(s) if there are additional service-connected conditions.

💰 Annual Dollar Impact at Key Rating Thresholds (2026)

Monthly VA compensation rates for a single veteran with no dependents:

Moving one rating tier from bilateral factor = $300–$1,400 more per month, every month for the rest of your life.

How to Check If the VA Applied It Correctly

Your VA rating decision letter should document each condition and the combined calculation. Here's how to audit it:

Request your C-file. The Rating Decision and rating worksheet in your C-file will show the exact calculation the VA used. Request via FOIA through va.gov or through your VSO.
Identify your bilateral conditions. List every condition on both sides of your body from your rating decision.
Check the worksheet. Find the section where the VA shows the combined calculation. Look for a "bilateral factor" adjustment line item. If it's not there, it may not have been applied.
Run the math yourself. Use the calculator above and the formulas in this guide to verify.
If bilateral factor was missed: File a Supplemental Claim citing the error and referencing 38 CFR § 4.26. Include your rating decision and a brief explanation of which bilateral pair was not adjusted. An accredited claims agent or VA attorney can do this quickly.

⚠ Don't Try to Calculate Your Final Combined Rating by Hand

The VA combined ratings formula is counterintuitive — 50% + 50% does NOT equal 100%; it equals 75%. The bilateral factor is applied before this formula, not after addition. If you run the math incorrectly, you may conclude the VA was right when they were wrong, or vice versa. Use our rating estimator tool or work with an accredited representative to verify.

Bilateral Factor Worksheet

📋 Printable Bilateral Factor Worksheet

Use this worksheet to document your bilateral conditions and calculate the bilateral-adjusted value for each pair. Bring this to your VSO, claims agent, or VA attorney appointment.

STEP 1: List Your Bilateral Condition Pairs

Body Part (Pair)	Left/Right Rating 1	Left/Right Rating 2	Sum	+10% BF	BF-Adjusted Value
e.g., Knees	20%	10%	30%	3%	33%

STEP 2: List Non-Bilateral Conditions

Condition	Rating
e.g., PTSD	50%

STEP 3: Combine All Using the Combined Ratings Formula

Start with your highest BF-adjusted value or single condition. Then combine with each subsequent condition using: New Combined = Existing + (New × (100% - Existing) / 100). Use a combined ratings table or our tool to verify the final number.

Frequently Asked Questions

What is the VA bilateral factor?

The bilateral factor is an adjustment under 38 CFR § 4.26 applied when you have ratable disabilities affecting paired extremities or organs (both knees, both ears, both shoulders, etc.). The paired ratings are added together, increased by 10%, and the adjusted value is used as the input to the standard combined ratings formula. It's required by regulation — not optional — whenever qualifying bilateral conditions exist.

Does bilateral hearing loss qualify for the bilateral factor?

Yes. Bilateral hearing loss (DC 6100) qualifies for the bilateral factor. However, tinnitus (DC 6260) does NOT qualify, even if it affects both ears, because it is rated as a single condition regardless of laterality. Many veterans have both; the bilateral factor applies only to the hearing loss ratings.

Can I file a claim if the VA missed the bilateral factor?

Yes. Request your C-file to verify the VA's rating worksheet. If the bilateral factor was not applied to qualifying conditions, file a Supplemental Claim citing 38 CFR § 4.26 as the basis for a corrected calculation. An accredited representative can help you draft the argument clearly.

Does bilateral neuropathy qualify?

Yes. Peripheral neuropathy in both hands, both feet, or both lower extremities qualifies. If you have neuropathy in all four limbs (both hands AND both feet), you apply the bilateral factor separately to each pair — once for the hands and once for the feet — then combine the adjusted values with your other conditions.

How does the bilateral factor affect SMC eligibility?

The bilateral factor can push your combined rating higher, which may bring you to or past thresholds needed for Special Monthly Compensation. SMC(s) (housebound) requires 100% combined plus an additional 60% SC condition — the bilateral factor can help reach either threshold. If you're near an SMC cutoff, have a VA attorney review whether the bilateral factor was correctly applied.

Think Your Bilateral Factor Wasn't Applied?

If you have conditions on both sides of your body and haven't verified the VA did the math right, it's worth a 5-minute free review.

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Editorial Standards: This article was written by Marcus J. Webb, a veterans benefits researcher specializing in 38 CFR Part 4 and VA rating math. Content is verified against current 38 CFR regulations. Last reviewed: June 2026. Not legal advice.