ChatGPT for restaurants: how to check its numbers

Yes, ChatGPT and other AI chatbots can help you run a restaurant: they draft, brainstorm and explain a formula in plain words. Where they slip is the exact figure or rule. Their makers say so on their own help pages, and one big city's business chatbot told owners they could do things the law doesn't allow. So use the answer, then check it. This post shows where a chatbot helps, where it goes wrong, and six steps to check an answer about your numbers.

Where a chatbot helps

A chatbot is fast at the jobs where a first try is worth having and you can judge the result yourself. Good uses in a restaurant:

• Drafting: a job post, menu descriptions, a note to staff about a new closing checklist, a polite email asking a supplier about a price change.
• Brainstorming: specials that use up trim, ways to fill a slow Tuesday, questions to bring to your accountant.
• Explaining: what prime cost means, why food cost is worked out from what you used and not what you bought, what a tip credit is.
• Sorting your own numbers: paste in a week of sales by day and ask it to lay them out, then check the sums.

In each of these, you are the check. You know if a menu description fits your food or if a schedule idea would work with your team. The trouble starts when the answer is a number or a rule you can't judge by reading it.

Where it goes wrong, in its makers' own words

OpenAI's help page, Does ChatGPT tell the truth?, says ChatGPT can give incorrect or misleading answers and may sound confident even when it's wrong. Among the mistakes it lists are wrong facts and made-up citations or sources. It also says the models learn from data up to a cutoff date, so they don't know what happened after it unless a tool like search is used. Its advice is to treat ChatGPT as a first draft, not a final source, and to check important information.

Google says much the same about its chatbot. Its Gemini help page says Gemini can hallucinate and present inaccurate information as fact, and that its answers shouldn't be relied on as legal, financial or other professional advice.

That's not a reason to stop using them. It's the makers telling you how to use them: as a helper whose work you check.

The New York City chatbot

The clearest warning for restaurant owners came from a city government. New York City announced its MyCity business chatbot in October 2023, built on Microsoft's Azure AI services, to answer owners' questions about city rules. In March 2024, The Markup reported that it told owners they could take a cut of their workers' tips, that a restaurant could go cash-free, and that there were no rules on telling staff about schedule changes. All three were wrong, the article reports: a 2020 city law, for one, requires businesses to accept cash.

The tips answer is wrong under federal law too. The US Department of Labor's fact sheet on tipped employees says an employer can't keep any part of employees' tips, whether or not it takes a tip credit, and that managers and supervisors can't take employees' tips either.

After the first story, the city added a note calling the bot a beta product and telling users not to treat its answers as legal or professional advice, but the bot stayed online. In January 2026, Mayor Zohran Mamdani named it as a place to save money and his office said the city planned to take it down, and an update on February 4, 2026 reports that the city has taken it down.

MyCity isn't ChatGPT, and the chatbot you use may well get the tip question right. The lesson is the pattern: an answer from an official-looking tool, said with confidence, that would have put an owner on the wrong side of the law. A general chatbot can make the same kind of mistake, and it won't tell you when it has.

Four places an answer about your numbers can slip

These are the things to look for in any answer about food cost, labor, prices or pay rules, whoever gives it.

• An old figure. Wage rates, tax rules and fees change. A model trained before the change can give last year's rate as if it were today's.
• The wrong formula. A sensible-sounding method can still measure the wrong thing, as in the example below.
• The wrong place. Federal law sets a floor, and many states and cities set their own rules on top of it.
• A source that doesn't say it, or doesn't exist. OpenAI lists made-up citations among the mistakes ChatGPT can make.

Example: the formula behind a food cost answer

Say you tell a chatbot what you spent on food last month and what you sold, and ask for your food cost. An answer that divides purchases by sales looks right, but it measures what you bought, not what you used. Food cost for a period counts the change in what's on your shelves:

Same month, about 3 points apart, and nothing in the first answer looks wrong. That's why the formula is the thing to check. The food cost percentage guide goes through it step by step.

How to check an AI's answer about your numbers

Six steps. The first three take a minute; the last three matter most when a rule or real money is involved.

1. 01Ask for the source, and open it. Ask the chatbot where the figure or rule comes from, then click the link yourself, as OpenAI's own help page suggests. If the page doesn't exist, or doesn't say what the answer says, drop the answer.
2. 02Check the formula. Ask it to write out the formula it used, step by step. Compare it with a formula you can trust: the restaurant formulas guide has food cost, labor, prime cost, break-even and more on one page.
3. 03Run your own numbers in a calculator that shows its math. RestaurantDoctorAI's free calculators for food cost, labor cost, prime cost and break-even each have a “How we worked it out” line that puts your own numbers into the formula, so you can check every step by hand. If the chatbot's answer and the calculator's don't match, find the step where they part.
4. 04Read the rule on the government page. For federal pay and tip rules that's the Department of Labor: its minimum wage page and its fact sheet on tipped employees. Look at the date on the page, too.
5. 05Check your state, and your city. The Labor Department says that when state and federal minimum wages differ, the worker gets the higher one, and its state minimum wage table lists each state. Federal law allows a tipped cash wage of $2.13 an hour, but some states require more and some allow no tip credit at all. The tipped minimum wage guide has the rate by state, and the deadline calendar lists tax, payroll and license dates for your state.
6. 06Take legal and tax questions to a person. When the answer decides what you pay staff, what you owe in tax or whether you need a permit, use the chatbot's answer as your list of questions for your accountant, lawyer or the agency itself.

Rules of thumb are not facts

Ask a chatbot what your food cost or labor cost should be and you'll get a range. It may be a fair rule of thumb, but it isn't a law, and it depends on what you sell. Ask where the range comes from and whether it fits your type of restaurant. The guides on this site name the source for each figure, and the targets the free check uses are listed as RestaurantDoctorAI's targets on the methodology page, with where each one comes from.

This week

1. 01Pick one number you've asked a chatbot about, or would like to: food cost, labor cost or a pay rate.
2. 02Ask it again, and this time ask for the formula and the source. Open the source.
3. 03Put the same numbers into the matching free calculator and open “How we worked it out”. Note any step that differs.
4. 04For any pay or tip rule, read your state's page and the Labor Department's page before you change a paycheck.