Mathematics · OpenAI

o3 Nano on AIME 2025: score, rank and what it means

o3 Nano scores 65.6 on AIME 2025, placing it #334 of 600 models in the index. The benchmark average is 63.6 and the leader is Claude Opus 4.5 Pro at 91.4.

Score
65.6
0–100 scale
Rank
#334
of 600
Percentile
44th
within the index
Benchmark avg
63.6
all models
Leader
91.4
Claude Opus 4.5 Pro
Gap to leader
25.8
points

Score distribution

The chart shows the top 10 models on AIME 2025, with o3 Nano highlighted. Longer bars mean higher scores.

Claude Opus 4.5 Pro 91.4
GPT-5.2 Pro 91.0
GPT-5.1 Pro 90.6
GPT-5.2 90.6
o4 Reasoning 90.3
o4 Pro 89.9
Claude Opus 4.5 89.8
Gemini 3 Pro Max 89.6
Claude Opus 4.5 Max 89.3
Claude Opus 4.5 Reasoning 88.9

Top 10 leaderboard

#ModelProviderContextInput / 1MAvg score
1 Claude Opus 4.5 Pro Anthropic 200000 $20.98 89.1
2 GPT-5.2 Pro OpenAI 2000000 $21.32 89.6
3 GPT-5.1 Pro OpenAI 200000 $19.77 87.8
4 GPT-5.2 OpenAI 2000000 $19.71 88.0
5 o4 Reasoning OpenAI 1000000 $19.69 87.5
6 o4 Pro OpenAI 1000000 $19.37 87.3
7 Claude Opus 4.5 Anthropic 400000 $19.42 87.7
8 Gemini 3 Pro Max Google DeepMind 2000000 $20.57 87.9
9 Claude Opus 4.5 Max Anthropic 1000000 $20.90 87.8
10 Claude Opus 4.5 Reasoning Anthropic 2000000 $20.91 88.2

What this score means

On AIME 2025, o3 Nano sits at #334 of 600. The leader, Claude Opus 4.5 Pro, scores 91.4, so the gap to the top is 25.8 points. The median model in this index scores 67.6, which puts o3 Nano below the midpoint.

OpenAI models average 80.9 on this benchmark. o3 Nano is 15.3 points below that provider line, so it is a weaker result than the average OpenAI model.

Among mid-range models, the average is 60.1. o3 Nano is 5.5 points above that group. This is the more useful comparison if you are shortlisting within the same tier rather than across the whole index.

Read a 65.6 as a relative signal, not an absolute guarantee. Benchmark scores depend on prompt format, evaluation harness and contamination controls. Use this page to narrow the shortlist, then test the model on your own data.

Price context

At $7.78 per million input tokens, o3 Nano is above the median input price of $4.00 across the 600 models scored on AIME 2025. The models immediately around it in the ranking are shown below so you can compare score and price together.

ModelProviderContextInput / 1MAvg score
Arctic Chat Snowflake 16384 $2.70 69.8
Grok 4 Nano xAI 16384 $8.97 72.7
Fusion OpenRouter 16384 $8.41 71.1
Nova Lite Max Amazon 200000 $9.79 73.4
o3 Nano OpenAI 32768 $7.78 70.6
Auto Pro OpenRouter 8192 $8.41 71.2
Mixtral Turbo Chat Together AI 32768 $3.02 71.7

Other benchmarks for o3 Nano

BenchmarkScoreRankPercentileRelative
MMLU-Pro 75.3 325 46th
GPQA Diamond 64.8 364 39th
SWE-bench Verified 57.9 358 40th
HumanEval 72.5 377 37th
MATH-500 74.5 339 44th
LiveCodeBench 60.3 365 39th
IFEval 78.2 365 39th
TruthfulQA 75.4 324 46th
HellaSwag 81.4 360 40th
MMMU 70.2 295 51th
Arena Elo 1354.5 355 41th

FAQ

What score does o3 Nano get on AIME 2025?

o3 Nano scores 65.6 on AIME 2025 in this index. The benchmark average is 63.6 and the top score is 91.4.

How does o3 Nano rank on AIME 2025?

It ranks #334 of 600 models, in the 44th percentile. The leader is Claude Opus 4.5 Pro at 91.4.

Is o3 Nano good at AIME 2025?

It is below the median for this benchmark, so test it carefully before relying on it for this capability. The result should be read alongside its price and context window.

How is the AIME 2025 score calculated?

AIME 2025 is a mathematics benchmark. Scores in this index are modelled estimates on a 0–100 scale (or Elo for Arena), derived from capability tier and benchmark difficulty. They are not official leaderboard results.

What does o3 Nano cost?

o3 Nano costs $7.78 per million input tokens and $29.81 per million output tokens.

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