Rating Math

Bilateral factor

VA disability calculator with the bilateral factor

Free, with no sign-up. Enter your ratings, tick the ratings that are for both arms, both legs or paired muscles, and see the combined rating with each step shown.

Last checked 2026-10-15. Sources and editorial standards

Your ratings

Tick the box above if so. A box then appears under each rating: tick the 2 to 4 ratings that are the paired ones.

Monthly compensation

At a combined rating of 10% or 20%, dependents do not change the rate.

Whole number from 0 to 20. Only available when the status above includes a child.

Whole number from 0 to 20. Only available when the status above includes a child.

Rates effective December 1, 2025. Estimate only.

What the bilateral factor is

When a partial disability affects both arms, both legs or paired skeletal muscles, the ratings for the two sides are combined as usual and then 10 percent of that value is added, not combined. The result is treated as one disability for ordering and for all later combinations. The rule is 38 CFR 4.26.

When it applies

  • The rule says the factor does not apply unless there is a partial disability of compensable degree in each of two paired extremities, or in paired skeletal muscles.
  • "Arms" and "legs" mean the upper and lower extremities as a whole. A compensable thigh disability on one side and a compensable foot disability on the other, for example, qualify.
  • When both upper and both lower extremities are affected, the four ratings are combined first and the 10 percent is added to that result.

A worked example

60%, 20%, 10% and 10%, where the two 10% ratings are both legs. The two 10% ratings combine to 19. Adding 10 percent of 19 gives 21. The ratings in order are now 60, 21 and 20. 60 with 21 gives 68, and 68 with 20 gives 74. Rounded to the nearest 10, the combined rating is 70%. This is the example printed in the rule.

The most favorable result

The rule adds that if leaving a paired rating out of the bilateral factor gives a higher combined evaluation, the paired rating is left out and combined separately. The calculator checks this and tells you when it applied.

How to use the calculator above

  1. Choose each of your ratings.
  2. Tick the box for the bilateral factor, which is already ticked on this page.
  3. Tick the 2 to 4 ratings that are the paired arms, legs or muscles.
  4. Press Calculate and read the steps.

For the basic method without the bilateral factor, see how ratings are combined. For the monthly amount at your combined rating, see the pay chart. This is an estimate, not a decision on any claim.