VA disabilityGuide
The VA bilateral factor, with worked examples
The question
When does the bilateral factor apply, and how much does it add?
Short answer
When both arms or both legs have a compensable rating, VA combines those ratings first, adds 10% of the result, rounds it to a whole number and treats it as one rating. Both arms and both legs together form one group, so four 20% ratings come out at exactly 70%.
Updated · sources read · Change log →
VA never adds disability percentages together. It combines them with the whole-person method in 38 CFR 4.25, which is why 50% and 30% make 65, not 80. The bilateral factor is the one step in that math that gives something extra back, and it only works when both sides of the body are affected.
This guide puts 38 CFR 4.26 into plain words and runs real numbers through it. Every result below comes from the same engine as our VA rating calculator, which follows Table I in 38 CFR 4.25 cell for cell.
When the bilateral factor applies
The regulation applies the factor to disabilities of both arms, both legs or paired skeletal muscles. Three details decide whether you have a pair:
- “Arm” and “leg” mean the whole limb. The regulation says the terms don’t separate the arm, forearm and hand, or the thigh, leg and foot. Its own example pairs a right-thigh amputation with flat feet on the left foot.
- Each side needs a compensable rating — 10% or more. A rated left knee and a 0% right knee isn’t a pair (4.26(c)).
- An arm and a leg are never a pair. A 10% left arm and a 10% right leg are combined the ordinary way.
Our calculator lets you tag ratings as left arm, right arm, left leg or right leg. Paired skeletal muscles aren’t in the calculator; VA applies the same steps to them.
The four steps, in order
- Combine the paired ratings with Table I, largest first. The result is the combined bilateral value.
- Add 10% of that value. The regulation says the 10% is added, not combined: plain addition, not another whole-person step.
- Round to the nearest whole number. The regulation’s text skips this step, but VA’s 2023 Federal Register rule explains its own example: 10 and 10 combine to 19, 1.9 is added, “resulting in 20.9. This is rounded to 21 (the nearest whole number).” Decimals of .5 or more round up.
- Treat the result as one rating. Put it in order of severity with your other ratings, combine as usual, and round to the nearest 10 only once, at the very end (4.25).
The bilateral step always comes first, before any other combining.
Seven worked examples
| Ratings | Bilateral value | Combined with the rest (largest first) | Combined value | Rating |
|---|---|---|---|---|
| 30% left leg, 30% right leg | 51 + 5.1 = 56.1 → 56 | none | 56 | 60% |
| 60%, 20%, 10% left arm, 10% right arm (the regulation’s example, which doesn’t name the limbs) | 19 + 1.9 = 20.9 → 21 | 60, 21 → 68; then 20 → 74 | 74 | 70% |
| 50%, 10% left leg, 10% right leg | 19 + 1.9 = 20.9 → 21 | 50, 21 → 61 | 61 | 60% |
| 40% left leg, 10% right leg, 30% | 46 + 4.6 = 50.6 → 51 | 51, 30 → 66 | 66 | 70% |
| 60%, 40%, 10% left arm, 10% right arm | 19 + 1.9 = 20.9 → 21 | 60, 40 → 76; then 21 → 81 | 81 | 80% |
| 10% left leg (nothing on the right leg), 30% | no pair, no factor | 30, 10 → 37 | 37 | 40% |
| 10% left arm, 10% right leg, 40% | arm and leg aren’t a pair | 40, 10 → 46; then 10 → 51 | 51 | 50% |
Look at the first row without the factor: 30 and 30 combine to 51, which rounds to 50%. The extra 5.1 points lift the combined value to 56 and the rating to 60%. At VA’s rates effective December 1, 2025, a veteran with no dependents is paid $1,132.90 a month at 50% and $1,435.02 at 60%.
The fourth row shows why the bilateral value is placed by size: 51 is larger than 30, so it goes first even though neither leg rating alone is the biggest number.
Both arms and both legs: one group, not two
Paragraph (b) of 4.26 covers a veteran with ratings on all four limbs. VA combines the ratings of all four extremities in order of severity and adds 10% once, to that single combined value.
With 20% on each arm and each leg:
- 20 and 20 combine to 36; with the third 20, 49; with the fourth 20, 59.
- 10% of 59 is 5.9, so the bilateral value is 64.9, which rounds to 65.
- 65 rounds up to 70% — an exact answer, not a range.
Reading the arms and the legs as two separate pairs would give a different result: each pair would be 36 + 3.6 = 39.6 → 40, and 40 and 40 combine to 64, or 60%. Paragraph (b) doesn’t allow that reading. With 30% on all four limbs the one-group method gives 76 + 7.6 = 83.6 → 84 → 80%.
The extra 5.9 points carry the combined value past 65, the point where VA rounds up to 70%.
With 20% on each arm and each leg, VA combines all four ratings to 59, adds 10% once (5.9), rounds 64.9 to 65 and rounds 65 to 70%. Without the factor the same ratings stop at 59, or 60%.
Combined value, 0–100 (whole-person scale).
When leaving the factor out pays more: 4.26(d)
Since April 16, 2023, paragraph (d) tells VA to drop one or more ratings from the bilateral calculation when that produces a higher combined evaluation. It happens near the top of the scale, where rounding can work against the factor.
Take ratings of 90%, 30%, 10% left arm and 10% right arm:
- With the factor: 90 and 30 combine to 93. The arms give 21. 93 and 21 combine to 94, which rounds down to 90%.
- Without the factor: 93 and 10 combine to 94; 94 and 10 combine to 95, which rounds up to 100%.
VA uses the more favorable result, 100%. This is the same arithmetic as the example in VA’s 2023 rule. Our calculator tries every way of leaving bilateral ratings out and says when 4.26(d) changes the answer.
What the factor doesn’t change
- Your individual ratings stay the same. The factor only changes how they combine. VA decides each rating; the arithmetic above only shows how the regulation combines them.
- The final rounding still happens once. A bilateral value of 56 isn’t rounded to 60 until everything else has been combined.
- TDIU looks at limbs as a unit. For the percentage part of the Individual Unemployability rule, 38 CFR 4.16(a) counts disabilities of one or both arms, or one or both legs, together with the bilateral factor, as one disability. Our dependents, TDIU and SMC-K guide explains that rule.
For the whole combining method, the rate table and the December 1 adjustment, see VA disability rates and VA math.
This is general information, not legal, tax, financial or medical advice.
Next step
Enter your ratings in the VA rating calculator and tag the ones on your arms and legs. It shows each step, the bilateral value, whether 4.26(d) applies and the monthly amount at VA’s current rates.
If you think VA left out the bilateral factor or combined your ratings differently, you can ask for help at no cost. Representatives of accredited Veterans Service Organizations never charge for help with VA benefit claims. Accredited attorneys and claims agents may charge only after VA has decided your initial claim, and only with a signed fee agreement on file with VA (38 CFR 14.636). VA explains how to find an accredited representative and answers common questions in its accredited representative FAQs.
The calculator for this guide
Sources
Each source was read on the date shown. When one changes, this guide and its date change with it.
- 38 CFR 4.26 — Bilateral factor
- 38 CFR 4.25 — Combined ratings table
- Schedule for Rating Disabilities: Exceptions to Applying the Bilateral Factor in VA Disability Calculations (interim final rule, 88 FR 22914)
- Current Veterans Disability Compensation Rates
- About VA disability ratings
- Get help from a VA accredited representative or VSO
- VA accredited representative FAQs
- 38 CFR 14.636 — Payment of fees for representation by agents and attorneys
Printed from Rank and Pay (rankandpay.com/guides/va-bilateral-factor/) · updated October 6, 2026 · general information, not an official statement.