Function Calling Overhead Calculator
See the token cost of sending tool schemas on every call.
Results update automatically as you type.
Result
$1,080.00/month in tool-schema overhead
1,440 tokens of schemas sent every call
- Tools
- 12
- Schema tokens (total)
- 1,440 tokens
- Overhead / call
- $0.00180
- Overhead / month
- $1,080.00
Tool/function schemas are sent as input tokens on every request. Estimate how much that overhead costs across your call volume.
How this is calculated
This calculator uses the agents formulas described in our methodology. All figures are estimates for planning; verify current pricing with each provider before relying on them.
Worked example (defaults)
With the default inputs above, here is the result:
Result
$1,080.00/month in tool-schema overhead
1,440 tokens of schemas sent every call
- Tools
- 12
- Schema tokens (total)
- 1,440 tokens
- Overhead / call
- $0.00180
- Overhead / month
- $1,080.00
Frequently asked questions
How do I reduce tool overhead?+
Send only the tools relevant to each request, trim schema descriptions, and cache the tool block if the provider supports it.
Does every call include all tools?+
By default yes — which is why large tool sets add up. Dynamic tool selection helps a lot.