Cheapest model that fits a 200k-token context
Teams with very long prompts often need to find the cheapest model that fits a 200k-token context. Because providers price input and output tokens very differently, the "obvious" model is rarely the cheapest. This tool compares them on your own workload so the decision is data-driven.
Start here: Model Context Window Comparison
Then: Will It Fit? Context Checker
Results update automatically as you type.
- Document
- 50,000 tokens
- Prompt / instructions
- 1,000 tokens
- Reserved for output
- 2,000 tokens
- Total needed
- 53,000 tokens
- Context window
- 128,000 tokens
- Docs of this size per call
- 2
Why this isn't trivial
The part people underestimate: few models support 200k tokens, and among those the input rate dominates because you are filling a huge window. In practice the biggest savings come from compressing context or using RAG so you need a smaller, cheaper window, so it is worth modelling before you commit.
How it's calculated
We estimate this by filtering models by context window, then ranking the qualifying ones by input cost at 200k tokens. Every figure uses the current provider prices baked into the site (reviewed daily), and you can override any input to match your own assumptions.
Frequently asked questions
Do I really need 200k tokens?+
Often not — RAG can retrieve just the relevant parts far more cheaply.
Why is filling a big window costly?+
You pay per input token, so 200k tokens is a large input bill every call.
Are these prices up to date?+
Yes. The model prices behind this calculator are refreshed and reviewed daily, so your estimate reflects current provider rates rather than a stale snapshot.
Related
Estimates for planning. Pricing data last reviewed 18 September 2026.