April 2025
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Claude vs OpenAI — Real API Cost Calculator

Compare actual monthly costs including prompt caching & batch discounts. Find the cheapest model for your workload.

Select models to compare
Claude
OpenAI
Monthly token volume
Input tokens / month 5M
025M50M75M100M
Output tokens / month 1.4M
06.25M12.5M18.75M25M
Prompt Caching Claude 90% off · OpenAI 50% off
Applies the provider's cached input rate. Best when reusing long system prompts or RAG context across many calls.
Batch API 50% off both providers
Non-urgent jobs processed within 24 hours at half price. Great for bulk analysis, document processing, nightly pipelines.
Monthly cost estimate
Anthropic
Claude Haiku 4.5
$0.00
per month
Cheaper ✓
OpenAI
GPT-4o mini
$0.00
per month
Claude OpenAI
Adjust the sliders to see your cost breakdown.
Saved via Caching
$0
vs standard input pricing
Saved via Batch API
$0
vs real-time pricing
API vs Claude subscription — which is cheaper?
Claude flat-rate subscriptions

At your current API estimate of $0/mo, here's how subscriptions compare:

Claude Pro
$20
~50 Opus 4 msgs/day
Sonnet + Haiku included
—
Max 5×
$100
5× more usage than Pro
All models
—
Max 20×
$200
20× more usage than Pro
All models + priority
—
Things to know
💾
Claude's caching is dramatically better
Claude offers up to 90% off cached input tokens vs OpenAI's 50%. For RAG apps with long system prompts, this can flip which provider is actually cheaper.
⚡
Stack batch + caching for maximum savings
Both discounts apply simultaneously. Claude Sonnet 4.6 cached + batch effective input rate drops to ~$0.15/M — nearly as cheap as GPT-4o mini.
📈
Output tokens dominate cost at scale
Output is 5–10× more expensive than input. Keep responses concise with clear instructions. Adding "be brief" to your system prompt can cut bills significantly.
⚠️
Long conversations compound fast
Each message in a thread re-sends the full conversation history as input. A 100-turn conversation can cost 50× more than 100 independent calls.