TaxCalcBench TY25
Professional Work · 2026-06-22
TaxCalcBench TY25 evaluates complete federal and state tax-return calculation from realistic taxpayer PDFs and companion structured data. Its headline strict score is the percentage of 50 cases for which every evaluated line on Form 1040, California Form 540, Illinois Form IL-1040, New York Form IT-201, or Virginia Form 760 exactly matches the expected return.
Top models (higher is better)
| Model | Score |
|---|---|
| GPT-5.6 Sol | 58.0 |
| GPT-5.5 | 54.0 |
| Claude Fable 5 | 34.0 |
| Opus 4.8 | 30.0 |
| Sonnet 5 | 6.0 |
| Kimi K3 | 6.0 |
| Gemini 3.5 Flash | 4.0 |
| Gemini 3.1 Pro Preview | 2.0 |