PromptCost — AI API Spend Estimator for Prompt Libraries
Why This is an Opportunity
It's a calculator with a token counter and a pricing table — could literally ship in a few hours. Every team running prompts at scale has been burned by an unexpected API bill.
Key Pain Points
- •Getting a $400 OpenAI bill because nobody checked how many tokens that system prompt was using
- •Manually counting tokens in tiktoken every time you modify a prompt
- •No way to estimate costs before deploying a new prompt to production
- •Leadership asks 'how much will this AI feature cost us monthly?' and you have to guess
Market Opportunity
AI Cost Management and FinOps for LLM API Spend
Current Size (2026)
$0.3B
Projected (2036)
$4.6B
CAGR
30.6%
This market is projected to grow 1347% over the next 10 years, reaching $4.6B by 2036.
Original Discovery
Teams building prompt databases have no idea what their prompts actually cost to run until the API bill shows up. PromptCost lets you paste in a prompt, pick the model, and instantly see token count, estimated cost per run, and projected monthly spend at different usage volumes. Simple calculator that saves teams from bill shock.
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