AI cost per client calculator Work out what an AI agent cost on a client, and what to bill for it.
Enter the hours an AI agent spent on a client, or its spend from your AI bill, plus your hourly rate and a markup. The calculator gives you the AI cost, the client's bill and your margin.
AI cost
Client bill
Margin
Margin %
How to use the AI cost per client calculator
Pick where the AI cost comes from. If you can read it straight off a bill, choose “I have the AI bill” and type the spend. If you only know the hours an agent ran, choose “Estimate from hours” and pick a preset, or enter your own dollar figure per agent-hour. Add your hourly rate and a markup on the AI cost, and the calculator fills in the client bill, the margin and the margin percent as you type.
- Choose a source: a known AI spend, or hours times a dollar-per-hour preset.
- Enter the hours you billed the client for.
- Enter your hourly rate and a markup on the AI cost, if you charge one.
- Read the AI cost, the client bill, the margin and the margin percent.
A worked example
An agent ran for 20 billed hours on a client’s project, at the typical preset of $5 per agent-hour. The freelancer’s rate is $100 an hour, with a 20% markup on AI cost.
| Line | Amount |
|---|---|
| AI cost (20 hours x $5) | $100.00 |
| Labor (20 hours x $100) | $2,000.00 |
| Markup (20% of AI cost) | $20.00 |
| Client bill | $2,120.00 |
| Margin | $2,020.00 |
| Margin percent | 95.3% |
The AI cost is a small slice of the bill here because the hourly rate is high relative to the per-hour AI cost. Change the preset to a heavier agent or drop the rate and the margin percent moves accordingly.
What counts as AI cost
Count the usage that would not exist without the client’s work: tokens, API calls or a share of a flat AI subscription for the hours spent on that client. Leave out AI usage on your own tools, marketing or other clients. If your AI provider bills per project or per API key, that number is the most accurate AI spend to enter directly.
Setting the right markup
A markup of 0% bills the AI cost at what it cost you, which works if the client already agreed to pay usage at cost. A markup in the 10 to 30% range is common when the freelancer also has to watch for runaway usage, pick the right model and clean up what the agent produces. Put your highest observed AI cost for a similar client through the calculator before quoting a flat rate, so a usage spike does not eat the margin.
Track the hours without adding them up by hand
This calculator needs you to remember the hours an agent ran and copy the AI spend from a bill. TimeUno records the time an AI tool spends working, waiting or done next to your own computer time, filed under the project, so the hours going into this calculator come from what was tracked rather than a guess. The AI time tracker page covers which tools it reads.
Start tracking client time 14-day trial, then $14.99 a month
Updated 13 October 2026
Questions people ask
How do I work out what an AI agent cost on a client?
Add up the hours an agent spent on the client's work and multiply by a dollar figure per agent-hour, or use the dollar amount from your AI provider's bill if you can split it by client. Either number goes in as the AI cost.
What dollar per agent-hour should I use?
It depends on the model and the plan. The presets here are rough starting points: a light assistant used for small edits, a typical coding agent and a heavy agent running long or parallel sessions. Replace any of them with your own number once you have a few AI bills to average.
Why does the calculator ask for a markup on top of my rate?
Your hourly rate covers your time. AI usage is a separate cost of doing the work, and a markup on it covers the risk of a usage spike plus the setup it took to run the agent well. A markup of 0 just passes the AI cost through at cost.
What is the difference between margin and margin percent?
Margin is the client bill minus the AI cost, in dollars. Margin percent is that margin divided by the bill. A bill of $2,120 with an AI cost of $100 has a margin of $2,020, or about 95% of the bill.
Is my data saved or sent anywhere?
No. The calculator runs in your browser and nothing you type leaves the page. Reset puts the starting numbers back.