Benchmark Almanac

TaxCalcBench

GPT-5.4 62.8% leads since March 2026
Not in model cards

Models compute complete US federal tax returns line by line from taxpayer data, with no tax engine. A return counts only when every evaluated line is exact.

Tax Year 2024 edition. The leaderboard still offers a TY 2024 view next to v2.

Made by
Column Tax
Released
July 2025
Kind
Finance
Level
Expert
Scored
Checked automatically
Answers
Short answer
Tasks
All public
Strongest model tested
GPT-5.4 Pro #19 on the capability index
Last model added
March 2026
Scores refreshed
November 12th, 2026

In the authors’ words

Can AI file your taxes? Not yet. Calculating US personal income taxes is a task that requires building an understanding of vast amounts of English text and using that knowledge to carefully compute results. We propose TaxCalcBench, a benchmark for determining models' abilities to calculate personal income tax returns given all of the necessary information. Our experiment shows that state-of-the-art models succeed in calculating less than a third of federal income tax returns even on this simplified sample set. Our analysis concludes that models consistently misuse tax tables, make errors in tax calculation, and incorrectly determine eligibility. Our findings point to the need for additional infrastructure to apply LLMs to the personal income tax calculation task.

Abstract of TaxCalcBench: Evaluating Frontier Models on the Tax Calculation Task (arXiv:2507.16126, CC0)
17
Models scored on its own leaderboard

2 models share the top score of 62.8% among models released by March 2026

Best score per model from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best.

The newest model with a score here came out in March 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 GPT-5.4 62.8%
  2. 2 GPT-5.4 Pro 62.8%
  3. 3 Claude Opus 4.6 52.9%
  4. 4 Gemini 3.1 Pro 49%
  5. 5 GPT-5 web search 41.7%
  6. 6 GPT-5.2 Pro 41.2%
  7. 7 Claude Sonnet 4.6 37.3%
  8. 8 Gemini 3 Pro 36.3%
  9. 9 Claude Opus 4.5 36.3%
  10. 10 GPT-5.2 33.8%
  11. 11 Gemini 2.5 Pro May 2025 32.4%
  12. 12 Claude Sonnet 4.5 31.4%
  13. 13 Claude Opus 4.1 28.4%
  14. 14 Claude Opus 4 27.4%
  15. 15 Gemini 2.5 Flash May 2025 26%
  16. 16 Claude Sonnet 4 23%
  17. 17 Claude Haiku 4.5 web search 13.7%

Source: Official TaxCalcBench leaderboard

#ModelScoreSettingDateSource
1 GPT-5.4 62.8% Mar 2026 Official leaderboard
2 GPT-5.4 Pro 62.8% Mar 2026 Official leaderboard
3 Claude Opus 4.6 52.9% Feb 2026 Official leaderboard
4 Gemini 3.1 Pro 49% Feb 2026 Official leaderboard
5 GPT-5 41.7% web search Aug 2025 Official leaderboard
6 GPT-5.2 Pro 41.2% Dec 2025 Official leaderboard
7 Claude Sonnet 4.6 37.3% Feb 2026 Official leaderboard
8 Gemini 3 Pro 36.3% Nov 2025 Official leaderboard
9 Claude Opus 4.5 36.3% Nov 2025 Official leaderboard
10 GPT-5.2 33.8% Dec 2025 Official leaderboard
11 Gemini 2.5 Pro May 2025 32.4% May 2025 Official leaderboard
12 Claude Sonnet 4.5 31.4% Sep 2025 Official leaderboard
13 Claude Opus 4.1 28.4% Aug 2025 Official leaderboard
14 Claude Opus 4 27.4% May 2025 Official leaderboard
15 Gemini 2.5 Flash May 2025 26% May 2025 Official leaderboard
16 Claude Sonnet 4 23% May 2025 Official leaderboard
17 Claude Haiku 4.5 13.7% web search Oct 2025 Official leaderboard

4 models have held number one on the official leaderboard since its release in July 2025

Lab claims count from the day the card came out, independent runs from the model’s release.

Google DeepMind OpenAI Anthropic
Own leaderboard Replaced by v2, Jun 2026
GPT-5.4 62.8%

Source: Official TaxCalcBench leaderboard

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard Best so far
0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) GPT-5.4 Claude Opus 4.6 GPT-5 Gemini 2.5 Pro 0% 20% 40% 60% 80% 100% 2025 2026 Near the ceiling (85%) GPT-5.4 Claude Opus 4.6

Source: Official TaxCalcBench leaderboard

No lab model card reports it yet

We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.

Versions

We switch the top row to each new version when it comes out. Open it for one row per version. An old version stays in play while people still test it, so whoever first takes it past 85% gets credit for closing it out.

Google DeepMind OpenAI Anthropic Meta
TaxCalcBench v2 9 leaders
Muse Wonder 83.7%
TaxCalcBench Replaced by v2, Jun 2026
GPT-5.4 62.8%
TaxCalcBench v2 5 leaders
Muse Wonder 83.7%

Source: Official leaderboards

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