GPT-5.5 vs Claude Opus 5 API Cost Calculator
Side-by-side FinOps unit economics audit comparing GPT-5.5 (OpenAI) against Claude Opus 5 (Anthropic). On an uncached 3:1 workload (3,500 input / 800 output tokens, 0% prompt cache), Claude Opus 5 cuts blended token spend by 11% and saves $14,400/mo ($172,800/yr) at 10,000 DAU. With 65% Prompt Caching enabled (interactive simulator default: $0.50/1M vs $0.50/1M cache reads), 10K DAU monthly spend is $112,545/mo (GPT-5.5) vs $98,145/mo (Claude Opus 5).
1. Side-by-Side Token Pricing, Context Window & Speed Matrix
Exact API pricing per 1 Million tokens (Input, Output, and Prompt Cache Read), maximum context window, and real-world streaming throughput.
| FinOps Metric | GPT-5.5 (OpenAI) | Claude Opus 5 (Anthropic) | Arbitrage Advantage |
|---|---|---|---|
| Input Price (per 1M tokens) | $5.00 / 1M | $5.00 / 1M | GPT-5.5 (1.0x cheaper) |
| Output Price (per 1M tokens) | $30.00 / 1M | $25.00 / 1M | Claude Opus 5 (1.2x cheaper) |
| Cached Input Read (per 1M) | $0.50 / 1M | $0.50 / 1M | Prompt Cache Hit Discount Ready |
| Blended 3:1 RAG Rate (per 1M) | $11.25 / 1M | $10.00 / 1M | 11% savings with Claude Opus 5 |
| Context Window / Max Output | 1.1M (1,050,000) / 128K out | 1M (1,000,000) / 128K out | GPT-5.5 larger context |
| Streaming Speed & TTFT | 96 tok/s (310ms TTFT) | 96 tok/s (310ms TTFT) | GPT-5.5 faster generation |
| Capabilities (Tools / Vision / Cache) | Tools: Yes · Vision: Yes · Cache: Yes | Tools: Yes · Vision: Yes · Cache: Yes | JSON Mode: Both Supported |
2. Monthly SaaS Cloud Bill Simulation (1,000 DAU / 10,000 DAU / 50,000 DAU)
Simulated monthly API spend for a production AI SaaS application (12 requests per active user/day, 3,500 input tokens + 800 output tokens per turn, 30 days/month).
| SaaS Scale Tier | Monthly Token Volume | GPT-5.5 Monthly Bill | Claude Opus 5 Monthly Bill | Monthly Savings (Claude Opus 5) |
|---|---|---|---|---|
| 1,000 DAU (Seed / MVP) | 1.26B in / 288M out | $14,940/mo | $13,500/mo | Save $1,440/mo |
| 10,000 DAU (Growth SaaS) | 12.6B in / 2.88B out | $149,400/mo | $135,000/mo | Save $14,400/mo ($172,800/yr) |
| 50,000 DAU (Enterprise Scale) | 63.0B in / 14.4B out | $747,000/mo | $675,000/mo | Save $72,000/mo |
Customize Your Exact DAU, Turns/Day & Prompt Cache Hit Rate
3. Prompt Caching Savings Math (At 10,000 DAU Workload)
Long system prompts, RAG document context, and multi-turn agent histories qualify for automatic or explicit prompt caching. Here is how cache hit rates change your monthly cloud bill:
| Prompt Cache Hit Rate | GPT-5.5 (Read @ $0.50/1M) | Claude Opus 5 (Read @ $0.50/1M) | Combined Hybrid Router + 75% Cache |
|---|---|---|---|
| 0% Cache Hit (Cold Prompts) | $149,400/mo | $135,000/mo | $137,880/mo |
| 50% Cache Hit (Standard Chat) | $121,050/mo | $106,650/mo | $109,530/mo |
| 75% Cache Hit (Production Agent/RAG) | $106,875/mo | $92,475/mo | $95,355/mo |
| 90% Cache Hit (Heavy Document Context) | $98,370/mo | $83,970/mo | $86,850/mo |
4. Multi-Provider Host Arbitrage & Latency Disparity Table (Cost vs. <400ms TTFT SLA)
Don't overpay default gateway markups or suffer peak-hour latency spikes. Compare verified inference hosts for both GPT-5.5 and Claude Opus 5 anchored by Cost-per-1M Tokens vs. Time-to-First-Token (TTFT < 400ms SLA):
| Model | Inference Host / Gateway | Input / 1M | Output / 1M | Cache Read / 1M | TTFT Latency & SLA | Throughput | Deploy / Credits Link |
|---|---|---|---|---|---|---|---|
| Claude Opus 5 | Anthropic Direct / Primary #1 Smart Router Pick | $5.00 | $25.00 | $0.50 | 292ms <400ms SLA ✓ | 96 tok/s | Deploy (Prompt Caching Ready) → |
| Claude Opus 5 | OpenRouter (0% Markup Failover) | $5.00 | $25.00 | $0.50 | 304ms <400ms SLA ✓ | 92 tok/s | Deploy (Unified API for 470+ Models) → |
| GPT-5.5 | DigitalOcean GPU Droplets (H100 / L40S) | $5.00 | $30.00 | $0.50 | 241ms <400ms SLA ✓ | 116 tok/s | Deploy (Dedicated H100 & L40S GPU Cloud) → Sign Up → |
| GPT-5.5 | RunPod Serverless vLLM ($5–$500 Bonus) | $5.00 | $30.00 | $0.50 | 255ms <400ms SLA ✓ | 110 tok/s | Deploy ($5–$500 Free Bonus Credit) → |
| GPT-5.5 | OpenAI Direct / Primary | $5.00 | $30.00 | $0.50 | 292ms <400ms SLA ✓ | 96 tok/s | Deploy (Route with 0% Markup Fallback) → |
| GPT-5.5 | OpenRouter (0% Markup Failover) | $5.00 | $30.00 | $0.50 | 304ms <400ms SLA ✓ | 92 tok/s | Deploy (Unified API for 470+ Models) → |
5. Frequently Asked Questions (GPT-5.5 vs Claude Opus 5)
6. Related FinOps Comparisons & Model Calculators
Drop Your Usage CSV, Paste Your System Prompt, or Rescue Your Monthly LLM Bill
100% browser-local FinOps auditing: drop your OpenRouter / OpenAI / Anthropic / Cursor usage CSV, count 20-turn agent loop bloat from your system prompt, or model instant savings across 61 models.
Export your 30-day activity CSV from OpenRouter, Anthropic Console, OpenAI Usage, or Cursor/Cline and drop it below (or paste raw CSV rows). Everything runs in your browser memory — no API keys or logs ever leave your device.
Embed Live Claude Opus 5 Token Price Badge in Your GitHub README or Docs
Keep your open-source repo or internal engineering wiki automatically synced with live Claude Opus 5 input/output pricing:
Multi-Turn Agent Context Overflow & Architecture-Specific FinOps Verdict (GPT-5.5 vs Claude Opus 5)
1. Multi-Turn Agent Context Window Ceiling: On a cumulative autonomous agent loop accumulating 6,800 tokens/turn (system prompt + tool JSON schema + conversation history), GPT-5.5 (1,050,000 token context window, 128,000 max output) reaches context saturation at Turn 154, whereas Claude Opus 5 (1,000,000 token context window, 128,000 max output) saturates at Turn 147.
2. Prompt Cache Hit Economics (90% vs 90% Read Discount): GPT-5.5 discounts cached prefix reads by 90% ($0.50/1M vs $5.00/1M uncached), while Claude Opus 5 discounts cached reads by 90% ($0.50/1M vs $5.00/1M uncached). At a 65% production cache hit ratio across 10,000 DAU, net monthly spend is $112,545/mo vs $98,145/mo.
3. Serverless API vs. Dedicated H100 vLLM Break-Even Threshold: Benchmarked against a dedicated $2,150/mo NVIDIA H100 80GB node (DigitalOcean H100 GPU Droplets / $300 Vultr GPU credit), serverless API billing on GPT-5.5 remains cheaper than dedicated GPU provisioning up to 191 DAU, while Claude Opus 5 breaks even against dedicated GPU hosting at 219 DAU.
With a massive 1,050,000-token context window, GPT-5.5 can ingest entire code repositories or multi-document corpora without vector chunking—provided your architecture pins static context at the top of the prompt for prefix caching ($0.50/1M cached read):
- 100,000-Token Full-Repo Prompt (0% Uncached): $524.00 per 1,000 queries
- 100,000-Token Prompt with 90% Prefix Cache Hit: $119.00 per 1,000 queries (saves $405.00 per 1K calls)
- Top-5 Vector RAG Retrieval (4,000-Token Chunk): $44.00 per 1,000 queries (lowest cost when cross-document global reasoning is not required).
Because Claude Opus 5 generates internal reasoning tokens (usage.completion_tokens_details.reasoning_tokens) before emitting visible output, every internal thinking token is billed at the full output rate of $25.00/1M:
- Visible Output Only (800 tok/call, 0 CoT): $20.00 per 1,000 API calls
- Medium Reasoning Effort (+1,400 CoT tok/call): $55.00 per 1,000 API calls (2.75x output multiplier)
- Deep Reasoning / Coding Effort (+3,200 CoT tok/call): $100.00 per 1,000 API calls (5.0x output bill multiplier)
- Production FinOps Guardrail: Cap
max_completion_tokensand route non-reasoning classification turns to a fast instruct tier so hidden CoT tokens do not erode SaaS seat margins.
