GPT-5 Cost Calculator

Estimate OpenAI GPT-5 API costs at $1.25 input / $10 output per 1M tokens, plus GPT-5 mini and GPT-5 nano.

GPT-5 is OpenAI's reliable production workhorse — released August 2025 with a 400K-token context window and configurable reasoning effort. At $1.25 per million input tokens and $10 per million output tokens it sits in a sweet spot of price and capability that still beats most 2026 flagships for everyday workloads.

Use this calculator to project the real-world API cost of running GPT-5 against your user volume and message frequency. Add GPT-5 mini ($0.25/$2.00) or GPT-5 nano ($0.05/$0.40) to compare side-by-side and find the right size for the job.

Models included

GPT-5 (OpenAI) — $1.25 input / $10.00 output per 1M tokens · 400K context window
GPT-5 mini (OpenAI) — $0.25 input / $2.00 output per 1M tokens · 400K context window
GPT-5 nano (OpenAI) — $0.05 input / $0.40 output per 1M tokens · 128K context window

Frequently asked questions

How much does GPT-5 cost per million tokens?

GPT-5 costs $1.25 per million input tokens and $10 per million output tokens as of May 2026. Cached input drops to $0.125 per million — a 90% discount for repeated context.

How does GPT-5 compare to GPT-5.5 and GPT-5.4?

GPT-5 ($1.25/$10) is OpenAI’s lowest-priced general-purpose flagship. GPT-5.4 ($2.50/$15) adds computer-use and a 1.05M context window. GPT-5.5 ($5/$30) is the current top-tier reasoning model.

What is the cheapest GPT-5 family model?

GPT-5 nano at $0.05 input / $0.40 output per million tokens — about 25× cheaper than GPT-5 itself. It is the best choice for classification, routing, and bulk extraction tasks.

What is the context window for GPT-5?

GPT-5 has a 400K-token context window. GPT-5 mini also gets 400K; GPT-5 nano is limited to 128K.