Prompt Context Budget Calculator

See remaining context after allocating prompt components.

Remaining context budget
68500 tokens
Inputs
tokens
Published model context limit; verify provider documentation.
tokens
System and developer instruction allocation.
tokens
History allocated to the request.
tokens
RAG or external context allocation.
tokens
Tool schemas and call instructions.
tokens
Reserved response budget.
Results & Graph
Remaining context budget
68500 tokens

Remaining context budget

Graph 1 • Calculator-specific flow Shows the calculated components and current result from this tool.
Remaining context budgetAllocated59.5kRemaining68.5kWindow128.0kRemaining context budget: 68500 tokens
Graph 2 • Modeled quantities Compares the values returned by the active calculation.
Allocated 59.5k Remaining 68.5k Window 128.0k
Graph 3 • Calculation checkpoints Displays the engine’s named calculation points in order.
0tokens 69.1ktokens 138.2ktokens Allocated: 59,500 tokens 59.5k Allocated Remaining: 68,500 tokens 68.5k Remaining Window: 128,000 tokens 128.0k Window
Summary: 46% of the entered context window is allocated.
Summary: 46% of the entered context window is allocated.
⚠️ Usable context may be lower than a published maximum; account for provider and tool formatting overhead.

Formula & Mathematical Methodology: Prompt Context Budget Calculator

Remaining context = context limit − system − history − retrieved context − tools − output reserve.
Remaining context = context limit − system − history − retrieved context − tools − output reserve.
  • Inputs: All units, rates, and allowances are entered by the user.

Rounding: Displayed values are rounded for readability; package and item quantities round upward.

Worked Example: A 128,000-token request budget

Use the default values to review the context budget estimate.

  1. Enter measured quantities and current user-supplied rates.
  2. Review the formula and assumptions below the result.
  3. Use the visualization to check the modeled input and output relationship.
Result: See remaining context after allocating prompt components.

Frequently Asked Questions

Are prices or rates updated automatically?

No. Enter the current rate from your provider, supplier, or utility. The tool does not claim live pricing.

Does this convert currencies?

No. A currency selector changes the display denomination only; it does not exchange values.

Developer Tools • AI & LLM Guide

How to Use the Prompt Context Budget Calculator: Practical Guide & Visual Analysis

Allocate a model context window across instructions, history, retrieved text, tools, and output reserve. Enter your own measurements, rates, and assumptions; the calculator runs locally in your browser. Whether you are researching llm context window budget, prompt token allocation calculator, context budget estimate, prompt context budget calculator, this interactive tool helps you allocate a model context window across instructions, history, retrieved text, tools, and output reserve.

Interpreting the 3 Custom Visual Graphs & Key Outputs

As you adjust Context Window, System Prompt, Conversation History, Retrieved Context, the calculator immediately computes Primary estimate, Input contribution breakdown, Sensitivity visualization and updates all three domain-specific SVG charts in real time. Instead of relying on a single static figure, you can inspect the primary domain diagram, component breakdown, and multi-point trajectory curve to see how changing your inputs shifts the final result. Use the Compare (up to 3 scenarios) button to evaluate side-by-side variations before making a decision.

Real-World Benchmark & Planning Tips (Global screening estimate; verify local units, product data, rates, and rules.)

In our benchmark scenario (A 128,000-token request budget), See remaining context after allocating prompt components. Keep in mind that entered values remain constant for the modeled interval. For related calculations in Developer Tools, explore LLM API Monthly Budget Calculator, AI Model Cost Comparison Calculator.