When you have permanent impairments to multiple body parts, the ratings are combined - not simply added - using the AMA Combined Values formula. This calculator shows the combined result and the estimated PPD dollar value.
PPD schedules verified through 10/01/2025.
Updated 10/01/2025
Combine Multiple PPD Ratings
Enter your PPD ratings for each body part. We'll combine them using the AMA formula and estimate the dollar value.
Verification notice
The AMA Combined Values formula is the standard method under Minn. R. 5223.0300, subp. 3E. Dollar amounts depend on the date of injury and the statutory PPD compensation schedule.
Date of injury
Optional - used to calculate the PPD dollar value from the schedule.
PPD ratings to combine
How PPD combination works
When you have multiple permanent impairments, they are not simply added together. Instead, Minnesota uses the AMA Combined Valuesformula: each successive rating is applied to the “remaining whole person” - the portion of whole-body function you still have after the previous ratings.
Formula: Combined = 1 − [(1 − A) × (1 − B) × (1 − C) × …]
Example: Two ratings of 10% each combine to 19% (not 20%), because the second 10% is applied to the remaining 90%.
This is an informational tool, not legal advice. Results depend entirely on the information you enter and may not reflect all statutory exceptions or fact-specific rules. Verify against the underlying statute and consult an attorney for case-specific decisions.
How this works
The AMA Combined Values formula prevents total impairment from exceeding 100%. Each new rating is applied to the remaining “whole person” after previous ratings. For example, a 10% rating followed by another 10% yields 19% combined - the second 10% is applied to the 90% of whole body function remaining after the first.
Why PPD ratings do not add straight up
When you have more than one impairment, Minnesota combines them with the formula A + B(1 − A), not simple addition.
Each additional rating applies only to the portion of the body not already impaired, so the combined value is always less than the straight sum and can never exceed 100%.
Worked example
Two 10% ratings combine to 19.0%, not 20%: 0.10 + 0.10 × (1 − 0.10) = 0.19. Ratings of 20% + 10% + 5% combine to 31.6%.
When to call
Use your result as a screen. Most claims that are on track do not need a lawyer; the ones that are off track usually do.
Green — may be on track
Your combined rating uses the statutory formula. Save it.
Yellow — worth watching
You may have additional ratable conditions not yet included. Keep your medical records handy.
Red — good reason to call
The insurer added or dropped ratings incorrectly, changing your PPD dollars. Call.
Frequently asked questions
- Why is 10% + 10% only 19%?
- Because the second rating applies only to the 90% of the body not already impaired by the first. The combining formula prevents double-counting.
- When do PPD ratings add instead of combine?
- Both happen. Some ratings within the schedule are added straight up, while ratings for different conditions are combined with the A + B(1 − A) formula. The rules specify which treatment applies to each rating, so the right answer depends on the exact rule numbers your doctor cited — mixing this up is a common way PPD dollars end up too low.
- Can combined ratings exceed 100%?
- No. The formula caps the whole-body impairment at 100%.