How much does an AI writing tool cost on GPT-5 Nano?
Running a copywriting / email-drafting tool with long outputs on GPT-5 Nano costs about $58.69/month for 800 users × 6 messages/day: that's $0.073 per user and $0.41 per 1,000 requests.
Monthly$58.69
Per user / mo$0.073
Per 1k requests$0.41
Quality index13
Change the numbers in the calculator →
Assumptions
- 800 users × 6 messages/day (144,000 per month)
- System prompt 1,200 tokens, user input 400, output 900 tokens
- Prompt cache hit rate 60%
- GPT-5 Nano list price: $0.05/1M input, $0.4/1M output, $0.005/1M cached input; context window 400,000 tokens
How GPT-5 Nano compares for an AI writing tool
1 of 14 other popular models are cheaper for this workload. Cheapest isn't always best: check the quality index, and consider routing easy requests to a cheap model and only hard ones to a frontier model.
| Model | Quality | Monthly | Per user |
|---|---|---|---|
| DeepSeek V4 Flash 0423 | 24.4 | $37.01 | $0.046 |
| GPT-5 Nano | 13 | $58.69 | $0.073 |
| Gemini 2.5 Flash Lite | 10.4 | $64.40 | $0.080 |
| Claude Haiku 5.5 | 43.4 | $80.24 | $0.10 |
| Llama 4 Maverick | 9.3 | $114 | $0.14 |
| DeepSeek V4 Pro 0423 | 30.4 | $153 | $0.19 |
| Grok 4.3 | 24.9 | $503 | $0.63 |
| Gemini 3.8 Flash | 40.9 | $594 | $0.74 |
| GPT-5.4 Mini | 24.1 | $686 | $0.86 |
| Grok 4.7 | 46.4 | $1,083 | $1.35 |
| Gemini 4 Argon | 52.6 | $1,435 | $1.79 |
| GPT-6.1 Sol | 51.8 | $1,594 | $1.99 |
| Claude Sonnet 5.5 | 56 | $1,594 | $1.99 |
| Claude Opus 5.5 | 57.6 | $3,189 | $3.99 |
| GPT-5.5 | 38.4 | $4,573 | $5.72 |
More GPT-5 Nano cost guides
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Prices: OpenRouter list prices (USD per 1M tokens), updated 2026-10-15. Estimates only; a month is 30 days. See how the math works.