What it does: Uses the prices you copy from OpenRouter's model pages and your real volume to estimate the monthly cost of an AI job.
Use it when: You're about to automate something with AI and have no idea what it will cost.
You get: The cost per run, per day and per month for each model, the math shown, and a safe monthly cap to set.
You are my cost checker, a pro with 10 years of pricing software jobs before they go live. Goal: work out what one AI job will cost per run, per day and per month on each model, so I can pick a model and set a safe monthly cap before I turn it on. Context: I'm about to automate a job in my business with AI. I need a real number, because a job that runs all day can cost far more than I guess. First, check that you can read the model prices I copied from OpenRouter's model pages. Tell me how many models you found, with the input and output price per 1M tokens for each. If they're missing, stop and ask me to paste them instead. Ask me these, then run. Skip any I already answered. 1. What does the AI do each time, and how many times a day? (Default: write [check: runs a day] and show the math for 100 runs a day so I can scale it.) 2. How long is a typical input and a typical output? (Default: paste one, or I use a 300 word input and a 150 word output and mark them (default).) Do this: 1. Estimate tokens: about 4 characters or 0.75 words per token in English. Count the instructions the AI gets each run as input too. If I didn't give them, use 200 words and mark it (default). Show the input and output tokens for one run. 2. Work out the cost of one run for each model. Show the math. 3. Multiply for a day and a 30 day month. 4. Add 30% for retries and longer inputs, and say that's a cushion, not a fact. 5. Suggest a monthly spending cap for each model's key: the cushioned month, rounded UP to the next whole dollar. Give me a table: model, cost per run, per day, per month, month with cushion, cap. Then the math for one model in 4 short lines. Example of the math lines with made-up prices, match this shape: "Input: 400 tokens x $3.00 / 1M = $0.0012. Output: 200 tokens x $15.00 / 1M = $0.0030. One run: $0.0042." Before you show me, check: - Every price in the table matches what I pasted from OpenRouter. - Run x runs a day x 30 equals the month, for every model. Check each one again. Rules: - Draft only. Ask me before you change any setting, key or cap. - Use only the prices I pasted. - Keep full numbers until the end. Show one run to 4 decimal places and a month to the cent. Then round the cap up. - Use only what is in my data and what I tell you. Never make up a name, number, date, price, link or promise. - If something you need is missing, write [check: what is missing] in that spot and keep going. Last, save these steps as a skill called 'AI Cost Math' so you do it this way each time I price an AI job. To run it again, just say: "Run my AI Cost Math skill."
You need
OpenRouter![]()
Any AITested on sample data
Built on Fanatical Prospecting's rule to know your numbers.
Copilot version
There is no separate Copilot version of this one yet. Paste the prompt above into Microsoft 365 Copilot Chat.
See a real example
Tested on sample data Oct 29 2026, after the rewrite: a Claude agent ran it on made-up sample input (tool results simulated). A separate Claude agent judged the run and the card.
Watch: no video for this one yet.
AuthorCorey Leon