At 6 requests/user/day (totaling 90,000 queries/mo), running Customer support chatbot on o3 (Reasoning Frontier) costs $2,425.50 / month ($4.851 / user / mo).
Total expected API invoice for 500 Active Users generating 90,000 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 (500 Active Users) | Cost / User / Mo | Annual Spend | Context Limit |
|---|---|---|---|---|---|
| o3 (Reasoning Frontier) (Current) | openai | $2,425.50 | $4.851 | $29,106.00 | 1,050,000 |
| GPT-5.6 Sol | openai | $1,527.75 | $3.056 | $18,333.00 | 1,050,000 |
| GPT-5.6 Cyber | openai | $3,819.375 | $7.639 | $45,832.50 | 1,050,000 |
| GPT-5.5 Standard | openai | $1,527.75 | $3.056 | $18,333.00 | 512,000 |
| GPT-5.5 Pro | openai | $9,166.50 | $18.333 | $109,998.00 | 512,000 |
| o3-pro (Frontier Reasoning) | openai | $4,851.00 | $9.702 | $58,212.00 | 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 500 Active Users is $2,425.50.
Assuming a 70% cache hit rate on repeated system and context tokens, prompt caching saves $1,984.50 per month ($23,814.00/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.