How do I budget tokens across a prompt?
Need to budget tokens across the parts of a prompt? Tokens are the unit AI providers bill in, and getting the count wrong throws off every cost estimate. This page helps developers designing prompts get an accurate count and the cost that follows from it.
Results update automatically as you type.
- System prompt
- 500 tokens
- Examples
- 0 tokens
- User message
- 300 tokens
- Total input
- 800 tokens
- Input cost / call
- $0.00100
- Context remaining
- 127,200 tokens
Why this isn't trivial
The part people underestimate: the window is a fixed budget shared by system prompt, examples, context and output, so overspending one starves another. In practice the biggest savings come from allocating the budget deliberately across prompt sections, so it is worth modelling before you commit.
How it's calculated
We estimate this by summing planned tokens per section against the window and the model's rates. 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
How do I split the budget?+
Reserve output first, then allocate the rest across system, examples and context.
What if I overspend?+
Trim the lowest-value section — often examples or verbose instructions.
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 28 July 2026.