Bilateral Factor Calculator
When service-connected disabilities affect both arms, both legs, or paired skeletal muscles, the VA combines those ratings first, then adds 10% of the combined value as a separate fourth rating. Use this tool to compute that bilateral-adjusted value before feeding it into the main Combined Rating Calculator.
Paired conditions
List only the ratings of paired extremities (e.g., left knee + right knee). Non-paired ratings go in the main calculator.
Bilateral factor only applies to paired body parts: both arms, both legs, or paired skeletal muscles on opposite sides of the body. Left knee + right shoulder does NOT qualify. The bilateral-adjusted value above is one input to the overall combined rating — combine it with any non-paired ratings in the main Combined Rating Calculator.
When the bilateral factor applies
Under 38 CFR 4.26, the bilateral factor adds a 10% increase to the combined value of paired-extremity disabilities. This is one of the most-overlooked aspects of VA math, and missing it can shift the rounded combined rating down by a full bracket. The adjustment is applied to the combined value of the pair, NOT to each rating individually, and is itself combined with other ratings using the standard 38 CFR 4.25 formula.