The VA bilateral factor, explained

It is 10% of a combined value

The bilateral factor is not an automatic additional 10 percentage points. Qualifying ratings are combined first. Ten percent of that combined value is added, and the resulting group is then combined with other disabilities.

Two qualifying 10% leg ratings combine to 19. Ten percent of 19 is 1.9, giving 20.9, treated as 21 for further combinations. That is different from adding 10 directly to the final rating.

Which body parts count?

The rule concerns both upper extremities, both lower extremities, or paired skeletal muscles. An arm includes the hand and forearm; a leg includes the foot and thigh. The conditions do not have to involve identical joints. A compensable disability must affect each side of a qualifying pair.

The calculator supports separately rated left and right arms and legs. “Other / neither” should be used for conditions such as tinnitus. Do not label separate hearing ratings as arm or leg disabilities. A single rating that already covers a bilateral condition should not be entered twice.

Four affected limbs

When both arms and both legs qualify, the eligible disabilities are combined into one bilateral group before the factor is applied. The calculator does not add separate arm and leg bonuses and then stack them.

The favorable-result exception

Section 4.26(d) requires removing one or more bilateral disabilities from the bilateral-factor calculation when combining them separately produces a more favorable combined evaluation. Our supported limb calculation compares eligible paired groupings and the calculation without the factor.

The tool accepts up to 12 individual ratings. Paired skeletal-muscle cases, amputation limits, and special diagnostic-code interactions require individual review. It is an estimate from your inputs, not a replacement for VA’s rating decision.

A complete example: two legs plus other ratings

Use this illustrative record: a 60% rating and a 20% rating marked “Other / neither,” plus separate 10% left-leg and 10% right-leg ratings. The official regulation uses these percentages to show the sequence.

Try these exact entries in the calculator. The result should show 70%, and the calculation details should identify the paired-leg group. Do not add a separate 10% row called “bilateral factor”; that would count a different disability rather than apply the factor.

Body-location choices: three practice records

These examples explain how to enter separately awarded ratings, not whether VA should award them.

• Left knee and right ankle: select left leg and right leg. The labels differ, but they identify opposite lower limbs.
• Left shoulder and left wrist: both belong on the left arm. These entries alone do not establish an opposite-side pair.
• Left knee and right wrist: select left leg and right arm. A leg and an arm are not a pair.

If your decision gives one percentage for a condition affecting both sides, keep it as one award. Do not divide that percentage or invent a second rating to make the calculator show a factor. Ask an accredited representative how that diagnostic code is treated if the award is unclear.

Why the final rating may stay the same

A bilateral adjustment changes a combined value before final rounding. That does not mean it always changes the final ten-point rating category. For example, two separate 10% leg ratings produce a bilateral group of 21, which still rounds to 20% when it is the entire record.

Read both the underlying calculation and the final rating. A missing change in monthly pay is not enough, by itself, to show that a bilateral calculation was omitted. If the calculator and your decision disagree, compare the individual entries first, then ask about the applicable rating rules. Our method and limitations describe what this tool supports.