At 40 requests/user/day (totaling 120,000,000 queries/mo), running AI coding assistant on Claude Fable 5 costs $18,624,000.00 / month ($186.24 / user / mo).
Total expected API invoice for 100,000 Active Users generating 120,000,000 queries.
Direct inference cost per MAU to model your SaaS pricing tiers and gross margins.
Savings generated by exploiting 60% cache hits on prompt context.
| Model | Provider | Monthly Spend (100,000 Active Users) | Cost / User / Mo | Annual Spend | Context Limit |
|---|---|---|---|---|---|
| Claude Fable 5 (Current) | anthropic | $18,624,000.00 | $186.24 | $223,488,000.00 | 1,000,000 |
| GPT-5.6 Sol | openai | $10,512,000.00 | $105.12 | $126,144,000.00 | 1,050,000 |
| GPT-5.6 Cyber | openai | $26,280,000.00 | $262.80 | $315,360,000.00 | 1,050,000 |
| GPT-5.5 Standard | openai | $10,512,000.00 | $105.12 | $126,144,000.00 | 512,000 |
| GPT-5.5 Pro | openai | $63,072,000.00 | $630.72 | $756,864,000.00 | 512,000 |
| o3-pro (Frontier Reasoning) | openai | $32,448,000.00 | $324.48 | $389,376,000.00 | 1,000,000 |
At 40 queries per user/day with Claude Fable 5, the estimated cost is $186.24 per monthly active user (MAU). Total monthly bill for 100,000 Active Users is $18,624,000.00.
Assuming a 60% cache hit rate on repeated system and context tokens, prompt caching saves $7,776,000.00 per month ($93,312,000.00/year) on Claude Fable 5.
With a direct COGS of $186.24 per user/month on Claude Fable 5, charging at least $931.20 per user/month ensures an 80%+ software gross margin.