GPT-4 Context Window Cost Calculator
From GPT-4o to GPT-4.1-nano, calculate exactly what OpenAI's GPT-4 family will cost your application at scale - per call, per day, and per month.
LLM Context Cost Calculator
Enter your usage parameters below
Number of tokens in your prompt per request
Number of tokens in the model response
Average number of API calls per day
$2.5/M input · $10/M output · 128k context
Cost Per Request
$0.022
GPT-4o - OpenAI
Daily Cost
$2.25
Monthly Cost
$67.50
Annual Cost
$810.00
Cost Per 1K Tokens
$0.0037
Blended input + output rate
Input vs Output Split
56% / 44%
Input cost vs output cost
Cheapest Alternative
GPT-4.1-nano
$2.70/mo - save 96% ($64.80/mo)
OpenAI · budget
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GPT-4 Model Pricing
| Model | Input $/1M | Output $/1M | Context | Category |
|---|---|---|---|---|
| GPT-4o | $2.50 | $10.00 | 128K | flagship |
| GPT-4o-mini | $0.15 | $0.60 | 128K | fast |
| GPT-4.1 | $2.00 | $8.00 | 1M | flagship |
| GPT-4.1-mini | $0.40 | $1.60 | 1M | fast |
| GPT-4.1-nano | $0.10 | $0.40 | 1M | budget |
Prompt Caching
OpenAI automatically applies 50% prompt caching discounts on repeated input prefixes. Applications with long system prompts or consistent context can halve their effective input token costs.
Frequently Asked Questions
How much does the GPT-4 API cost?
GPT-4o is priced at $2.50 per 1M input tokens and $10.00 per 1M output tokens. GPT-4.1 costs $2.00/1M input and $8.00/1M output, with a 1M token context window. GPT-4.1-mini is significantly cheaper at $0.40/1M input and $1.60/1M output. For a typical chatbot exchange (1,000 input + 500 output tokens), GPT-4o costs about $0.0075 per message.
What is GPT-4's context window size?
GPT-4o and GPT-4o-mini have a 128,000 token context window. GPT-4.1, GPT-4.1-mini, and GPT-4.1-nano all have a 1,000,000 (1M) token context window - sufficient for embedding entire codebases or lengthy documents. At $2.00/1M input tokens, processing a full 1M token context with GPT-4.1 costs $2.00 in input tokens alone.
Which GPT-4 model is most cost-effective?
GPT-4.1-nano at $0.10/1M input and $0.40/1M output is the most cost-effective GPT-4 family model, suited for classification, extraction, and simple generation tasks. GPT-4.1-mini ($0.40/$1.60) balances cost and quality for most production workloads. GPT-4o and GPT-4.1 are best reserved for complex reasoning, coding, and tasks where output quality directly drives user value.
Does OpenAI offer prompt caching for GPT-4?
Yes. OpenAI's Prompt Caching automatically reduces costs for repeated prompt prefixes. Cached input tokens are billed at 50% of the standard input price. This is particularly valuable for applications with long system prompts or repeated context (like RAG with consistent document sets), potentially halving your input token costs.
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