| Input per 1M tokens | $5 |
| Output per 1M tokens | $30 |
| Cache read per 1M tokens | — |
| Status | active |
| Source | official pricing page · verified 2026-09-07 |
Named migration target for gpt-5, o3, o1, gpt-4 retirements.
Example costs
- One request (2,000 in / 500 out): $0.0250
- 100K such requests/month: $2,500
- 1M input + 1M output tokens: $35
Compare against other models →
How GPT-5.5 compares on rate
GPT-5.5 runs $5 input / $30 output per MTok — a combined $35 for 1M tokens each way. The cheapest active model in our table, Gemini 2.5 Flash-Lite at $0.1/$0.4 (combined $0.5), is about 99% cheaper on combined rate (verified 2026-09-07).
Cheapest active OpenAI alternative: GPT-5.6 Luna at $0.2/$1.2 per MTok — combined $1.4 against $35, about 96% less.
Per-token rate is not per-task cost — tokenizers differ between model families, so benchmark with your own payloads before switching.
What real volumes cost at GPT-5.5 rates
Straight rate-card math at the verified $5/$30 per-MTok prices, assuming a 75% input / 25% output token split — no caching or batch discounts applied.
| Volume | Split | Cost at GPT-5.5 rates |
|---|---|---|
| 100K tokens in a day | 75,000 in + 25,000 out | $1.12 |
| That pace over a 30-day month (3M tokens) | 2.25M in + 750K out | $33.75 |
| 1M tokens in a month | 750,000 in + 250,000 out | $11.25 |
| Heavy month — 12M tokens | 9M in + 3M out | $135 |
Change the split or volume in the calculator — same verified rates, your numbers. Method + the corrections that make estimates real: how to estimate LLM API costs.
Frequently asked questions
What does GPT-5.5 cost per million tokens?
GPT-5.5 costs $5 per 1M input tokens and $30 per 1M output tokens on the OpenAI API (verified 2026-09-07).
How much does 100K tokens a day cost on GPT-5.5?
At a 75% input / 25% output split, 100K tokens costs about $1.12 at GPT-5.5 rates — about $33.75 over a 30-day month. That is straight rate-card math, before any caching or batch discounts.
Is there a cheaper model than GPT-5.5?
Yes — the cheapest active model we track is Gemini 2.5 Flash-Lite at $0.1/$0.4 per MTok, a combined $0.5 against GPT-5.5's $35 — about 99% less on combined rate (verified 2026-09-07). Tokenizers differ between families, so benchmark per-task cost with your own payloads.
How much do 1M input + 1M output tokens cost on GPT-5.5?
$35 — $5 for the input million plus $30 for the output million, at OpenAI rates verified 2026-09-07.