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.