Simulating realistic Agentic workflow parameters (40,000 in / 1,500 out with 65% cache reuse). Gemini 2.5 Pro delivers a 68% cost reduction over GPT-5.5 Standard.
| Traffic Volume Tier | GPT-5.5 Standard Monthly | Gemini 2.5 Pro Monthly | Monthly Savings by picking Gemini 2.5 Pro |
|---|---|---|---|
| 1,000 reqs/mo (Dev/Testing) | $128.00 | $40.625 | Save $87.375 / mo |
| 10,000 reqs/mo (Small App) | $1,280.00 | $406.25 | Save $873.75 / mo |
| 100,000 reqs/mo (Growth Production) | $12,800.00 | $4,062.50 | Save $8,737.50 / mo |
| 1,000,000 reqs/mo (Scale SaaS) | $128,000.00 | $40,625.00 | Save $87,375.00 / mo |
Gemini 2.5 Pro is 68% cheaper for Agentic workflow workloads. At standard Agentic workflow parameter ratios (40,000 input tokens, 1,500 output tokens, 65% cache hit), Gemini 2.5 Pro costs $0.0406 per request compared to $0.128 on GPT-5.5 Standard.
GPT-5.5 Standard offers a context window of 512,000 tokens (max output: 64,000), while Gemini 2.5 Pro offers 1,000,000 tokens (max output: 32,768).
At 100,000 requests per month, using Gemini 2.5 Pro saves $8,737.50 every month (or $104,850.00 annually) compared to GPT-5.5 Standard.
Prompt caching is the single biggest lever — each step re-reads prior context. Summarize or prune tool outputs before appending them to the transcript. Cap the step budget; runaway loops are the #1 surprise on agent invoices.