If you have more than one service-connected condition, your ratings are not added together. VA combines them with its own method, and the result is almost always lower than the sum. Two ratings of 50% and 30% make 70%, not 80%. Three ratings of 40%, 20% and 10% make 60%, not 70%. Once you see how the method works, the numbers stop being a mystery.
VA starts by treating you as a whole, healthy person, 100% “efficient”. Each rating then takes its percentage from whatever efficiency is left, starting with the largest rating. With 50% and 30%, the 50% rating leaves you at 50. The 30% rating then takes 30% of that remaining 50, which is 15, and leaves 35. Your combined value is 100 minus 35, or 65.
The rounding step
The combined value is rounded to the nearest 10 to get your official rating. A value ending in 5 or higher rounds up, so 65 becomes 70%. A value of 64 would have rounded down to 60%. This rounding is why small changes can matter a lot: a new 10% rating can push a combined value across a rounding line and lift the official rating, or it can change nothing at all.
Take three ratings of 40%, 20% and 10%. The 40% leaves 60. The 20% takes 12 of that, leaving 48. The 10% takes 4.8, leaving 43.2. The combined value is 56.8, which counts as 57 and rounds up to 60%.
The bilateral factor
When you have ratings on both arms, both legs or paired skeletal muscles, VA gives extra weight to that pair. It first combines the paired ratings with each other, then adds 10% of that combined value, and only then combines the result with your other ratings. Two knees rated 10% each combine to 19. Adding the bilateral factor of 1.9 gives 20.9, which then goes into the main calculation like a single rating.
What the rating pays
Your official rating sets your monthly payment. As of the rates effective December 1, 2025, a veteran alone receives $180.42 at 10%, $1,132.90 at 50%, $1,808.45 at 70% and $3,938.58 at 100%. From 30% upward, a spouse, children and dependent parents each raise the payment. At 70%, a veteran with a spouse and one child receives $2,074.45 a month. All of it is tax-free.
Using the calculator
The VA combined rating calculator shows every step above for your own ratings, including the bilateral factor, and turns the result into a monthly payment for your family. Its what-if table shows what a new rating or an increase on an existing one would do, which helps you see whether a claim could change your official rating at all.
Questions
Can my combined rating ever go down when I add a rating? No. Adding a rating can only keep the combined rating the same or raise it.
Why does 90% plus 10% not make 100%? A 90% rating leaves 10 efficiency, and 10% of 10 is 1, so the combined value is 91, which rounds down to 90%. Reaching 100% this way takes a combined value of 95 or more.
Is a 100% rating the same as unemployability? No. Individual unemployability pays at the 100% rate for veterans who cannot keep a steady job because of service-connected conditions, even when their combined rating is lower. It follows separate rules.