The PD Ratings Calculator is our most-used free tool — and the best example of how Glass Box AI works in practice. Here's a technical look at what happens when you calculate a Permanent Disability rating.
The Calculation Pipeline
California PD ratings follow a specific statutory formula defined by the PDRS (Permanent Disability Rating Schedule). Our calculator implements every step of this formula and shows you each one:
Step 1: Impairment Rating
The process starts with the Whole Person Impairment (WPI) from the treating or evaluating physician. This is based on the AMA Guides to the Evaluation of Permanent Impairment, 5th Edition — the standard mandated by California Labor Code §4660.1.
The calculator accepts the WPI percentage and the specific body part or system affected. Each input maps to a specific impairment code in the PDRS.
Step 2: PDRS Conversion
The WPI is converted to a standard disability percentage using the PDRS conversion tables. This step accounts for the specific nature of the impairment — how it affects the worker's ability to perform their occupation.
Our calculator shows you the exact PDRS code used, the conversion factor applied, and the resulting standard disability percentage. No hidden math.
Step 3: Age and Occupation Adjustments
California law adjusts PD ratings based on the injured worker's age at the time of injury and their occupation. The PDRS defines specific adjustment factors for different occupational groups.
The calculator displays the occupational group code, the age adjustment factor, and how each modifies the base rating. You can see exactly how a 45-year-old construction worker gets a different adjustment than a 30-year-old office worker — and why.
Step 4: Apportionment
Under Labor Code §4663 and §4664, PD ratings may be apportioned to account for pre-existing conditions or prior awards. The calculator handles both types:
- Medical apportionment (§4663) — based on the physician's opinion of causation
- Prior award apportionment (§4664) — based on overlap with previous disability awards
Step 5: Final Rating
The final PD rating determines the injured worker's benefit amount under the current PDRS. The calculator shows the complete chain: WPI → PDRS conversion → adjustments → apportionment → final rating → benefit amount.
Why Transparency Matters Here
PD ratings directly determine how much money an injured worker receives. A 1% difference in rating can mean thousands of dollars. When the calculation is invisible, errors go unchallenged.
With the Glass Box calculator, both applicant and defense attorneys can verify every step. If there's a dispute about the rating, you can point to the exact step where you disagree — not just argue about the final number.
Built on the Same Engine as Adjudica
The PD Calculator uses the same rating engine that powers Adjudica.ai's full case management platform. When you use the free calculator, you're experiencing the same transparent AI that Founding Firms use for their entire practice.
Try the PD Calculator — it's free, it shows its work, and it's the standard we hold every Glass Box tool to.