The AI API cost comparison calculates your estimated monthly spend across major LLM providers based on your input/output token volume. Enter your usage to compare GPT-4o, Claude, and Gemini side by side.
How to Calculate LLM API Costs
LLM API pricing is per 1M tokens (or per 1K tokens at some providers). Input tokens (your prompt) and output tokens (the model's response) are priced separately, with output tokens typically costing 2-4x more. Use this calculator to compare providers before committing to one.
Estimating Your Token Volume
1 token ≈ 4 characters of English text. A typical 200-word prompt is roughly 250-300 tokens. At 1000 requests/day with 500 input and 200 output tokens, you're using 700K tokens/day or 21M tokens/month. Use these numbers to find the cost breakpoint between models.
Frequently Asked Questions
Is this AI cost comparison tool free?
Yes, completely free with no signup required.
How current is the pricing data?
Pricing data reflects known rates as of early 2026. LLM pricing changes frequently — always verify current rates at each provider's official pricing page before making production decisions.
What is the difference between input and output tokens?
Input tokens are the tokens in your prompt (system message + user message + conversation history). Output tokens are the tokens in the model's response. Output tokens typically cost 2-4x more than input tokens because they require more computation.
Which LLM is cheapest for my use case?
It depends on your input/output ratio and quality requirements. For high-volume, short-response use cases (classification, extraction), GPT-4o-mini and Claude Haiku are typically cheapest. For complex reasoning tasks requiring long responses, the cost difference between models narrows relative to quality gains.
How do I estimate my monthly token volume?
Multiply your average prompt length (in tokens, approximately 4 chars per token) by requests per day by 30. For a typical chatbot with 500-token prompts and 200-token responses at 1000 requests/day: (500 + 200) × 1000 × 30 = 21M tokens/month.