At 6 requests/user/day (totaling 450,000 queries/mo), running Customer support chatbot on o3 (Reasoning Frontier) costs $12,127.50 / month ($4.851 / user / mo).
Total expected API invoice for 2,500 Active Users generating 450,000 queries.
Direct inference cost per MAU to model your SaaS pricing tiers and gross margins.
Savings generated by exploiting 70% cache hits on prompt context.
| Model | Provider | Monthly Spend (2,500 Active Users) | Cost / User / Mo | Annual Spend | Context Limit |
|---|---|---|---|---|---|
| o3 (Reasoning Frontier) (Current) | openai | $12,127.50 | $4.851 | $145,530.00 | 1,050,000 |
| GPT-5.6 Sol | openai | $7,638.75 | $3.056 | $91,665.00 | 1,050,000 |
| GPT-5.6 Cyber | openai | $19,096.875 | $7.639 | $229,162.50 | 1,050,000 |
| GPT-5.5 Standard | openai | $7,638.75 | $3.056 | $91,665.00 | 512,000 |
| GPT-5.5 Pro | openai | $45,832.50 | $18.333 | $549,990.00 | 512,000 |
| o3-pro (Frontier Reasoning) | openai | $24,255.00 | $9.702 | $291,060.00 | 1,000,000 |
At 6 queries per user/day with o3 (Reasoning Frontier), the estimated cost is $4.851 per monthly active user (MAU). Total monthly bill for 2,500 Active Users is $12,127.50.
Assuming a 70% cache hit rate on repeated system and context tokens, prompt caching saves $9,922.50 per month ($119,070.00/year) on o3 (Reasoning Frontier).
With a direct COGS of $4.851 per user/month on o3 (Reasoning Frontier), charging at least $24.255 per user/month ensures an 80%+ software gross margin.