Prompt Cost Calculator | Calculate AI Prompt Costs
Prompt Cost Calculator
Estimate how much your AI prompt costs based on prompt length, output tokens, AI model, and usage. Calculate cost per prompt, per 1,000 requests, and monthly usage.
Quick Answer
AI prompt cost depends mainly on the number of input tokens, output tokens, and the model you use. Enter your prompt below to estimate its token count and calculate the approximate API cost.
Calculate Your Prompt Cost
Approximate number of tokens the AI will generate.
Cost Formula
Prompt Cost = (Input Tokens × Input Price) + (Output Tokens × Output Price)
Estimated Prompt Cost
Input Cost
$0.000000
Output Cost
$0.000000
Input Tokens
0
Total Tokens
0
Cost / 1,000 Requests
$0
Monthly Cost
$0
Monthly Tokens
0
AI Model Prompt Cost Comparison
Compare the approximate cost of processing the same prompt across popular AI models.
| Model | Input / 1M | Output / 1M | Example Prompt |
|---|---|---|---|
| GPT-5.6 Sol | $4.00 | $20.00 | $0.010000* |
| GPT-5.6 Terra | $2.00 | $12.00 | $0.006000* |
| GPT-5.6 Luna | $0.20 | $1.20 | $0.000600* |
| Claude Sonnet 5 | $2.00 | $10.00 | $0.005000* |
| Gemini 3.7 Flash | $0.75 | $3.75 | $0.001875* |
| Gemini 2.5 Flash-Lite | $0.10 | $0.40 | $0.000200* |
*Example assumes 1,000 input tokens and 500 output tokens. Actual cost varies with token usage and model pricing.
What Affects Prompt Cost?
Prompt Length
Longer prompts generally contain more input tokens and therefore cost more to process. System instructions, examples, conversation history, and attached content can also increase input token usage.
Output Length
Generated output is normally priced separately from input tokens. A model producing longer responses can therefore increase the total cost of a request.
AI Model
Different AI models have different input and output token prices. Choosing a smaller model for simple tasks can significantly reduce cost.
Repeated Prompts
Applications that send the same or similar instructions thousands of times can accumulate substantial API costs.
Prompt Cost Examples
Short Prompt
Simple questions, classifications, short summaries, and basic instructions usually require relatively few input tokens.
Content Generation
Blog posts, product descriptions, emails, and long-form content can use significantly more output tokens.
Large Context
Documents, conversation history, examples, and large system prompts can increase the number of input tokens processed per request.
Related AI Cost & Developer Tools
Prompt Cost Calculator FAQ
How is prompt cost calculated?
Prompt cost is generally calculated using the number of input tokens and output tokens multiplied by the applicable price per million tokens.
How many tokens does my prompt contain?
The calculator provides an estimate. Exact tokenization depends on the model and tokenizer being used.
Does a longer prompt cost more?
Usually, yes. A longer prompt generally contains more input tokens, increasing the input portion of the API cost.
Is prompt cost the same across AI models?
No. Each model can have different input and output token prices, so the same prompt may cost different amounts depending on the model.
Is the token estimate exact?
No. This calculator uses an approximate token estimate. Actual token counts depend on the tokenizer, model, language, formatting, and content.
Estimates are for informational purposes only. AI provider pricing and tokenization can change. Always verify current pricing with your AI provider.
Last reviewed: September 3, 2026