Calculate exact API token costs across GPT-4o, Claude 3.5, Gemini 1.5, and DeepSeek. Estimate monthly cloud AI bills before launching SaaS applications.
$0.00875
$8.75
Large Language Models (LLMs) charge separately for Input Tokens (the prompt context and system instructions you send) and Output Tokens (the generated text response). Because generating output requires autoregressive token prediction, output tokens are typically 3x to 4x more expensive than input tokens.
As a general rule of thumb for English text, 1,000 tokens ≈ 750 words (roughly 1.33 tokens per word). Code, non-English languages, and JSON formatting consume slightly more tokens per character.
To slash your monthly AI bill: use prompt caching for static instructions, switch routine tasks to lightweight models (like GPT-4o-mini or Claude 3.5 Haiku), and implement semantic response caching with Redis.