At 8 requests/user/day (totaling 24,000,000 queries/mo), running Agentic workflow on GPT-5.5 Pro costs $18,432,000.00 / month ($184.32 / user / mo).
Total expected API invoice for 100,000 Active Users generating 24,000,000 queries.
Direct inference cost per MAU to model your SaaS pricing tiers and gross margins.
Savings generated by exploiting 65% cache hits on prompt context.
| Model | Provider | Monthly Spend (100,000 Active Users) | Cost / User / Mo | Annual Spend | Context Limit |
|---|---|---|---|---|---|
| GPT-5.5 Pro (Current) | openai | $18,432,000.00 | $184.32 | $221,184,000.00 | 512,000 |
| GPT-5.6 Sol | openai | $3,072,000.00 | $30.72 | $36,864,000.00 | 1,050,000 |
| GPT-5.6 Cyber | openai | $7,680,000.00 | $76.80 | $92,160,000.00 | 1,050,000 |
| GPT-5.5 Standard | openai | $3,072,000.00 | $30.72 | $36,864,000.00 | 512,000 |
| o3-pro (Frontier Reasoning) | openai | $10,848,000.00 | $108.48 | $130,176,000.00 | 1,000,000 |
| o3 (Reasoning Frontier) | openai | $5,424,000.00 | $54.24 | $65,088,000.00 | 1,050,000 |
At 8 queries per user/day with GPT-5.5 Pro, the estimated cost is $184.32 per monthly active user (MAU). Total monthly bill for 100,000 Active Users is $18,432,000.00.
Assuming a 65% cache hit rate on repeated system and context tokens, prompt caching saves $16,848,000.00 per month ($202,176,000.00/year) on GPT-5.5 Pro.
With a direct COGS of $184.32 per user/month on GPT-5.5 Pro, charging at least $921.60 per user/month ensures an 80%+ software gross margin.