Which tool to choose
You don't need anything expensive. The choice comes down to one thing: how much you want the AI to do for you.
You want to understand your money and have a written plan, at zero cost. Use ChatGPT free. You give it the numbers by voice or copy-paste, and it gives you back the split by categories, the savings target and the advice. It's the right option for most readers: no link to your account, no subscription. The latest model is also accessible to free users, with tighter usage limits than the paid plans.
You want expenses to be logged and categorized on their own. Here you need a dedicated app that connects to your transactions. YNAB if you like the strict "every euro has a job" approach: it tracks expenses in real time, categorizes transactions and shows where the money goes. Monarch if you want to see investments and net worth alongside the budget, but it costs more: $99.99 a year if you pay annually, or $14.99 a month.
You have little discipline and need a push. Cleo works like a chat and is the most engaging, known for its "roast mode" that comments aggressively but jokingly on your bad spending habits.
The practical advice: start with ChatGPT free. If after two months you feel that logging expenses by hand is a burden, consider a paid app. Don't buy a subscription before you know whether the method works for you.
How to do it
Let's go with ChatGPT, because it's free and covers the most common case. From browser or app the path is identical: open a new chat and follow these steps.
Gather three numbers before you write: your net monthly salary (what lands in your account), the total of your fixed expenses (rent/mortgage, utilities, subscriptions, installments) and an estimate of your variable expenses (groceries, transport, leisure).
Paste the prompt below, replacing the figures with your real ones:
Act as a personal finance advisor. Build me a monthly budget using the 50/30/20 method.
My data:
- Net monthly salary: €1,500
- Fixed expenses: rent €500, utilities €120, subscriptions €35, phone €15
- Estimated variable expenses: groceries €300, transport €80, leisure €150
I want you to:
1. Split my expenses into needs, wants and savings, showing for each category both the ideal percentage of the 50/30/20 method and how much I'm actually spending.
2. Tell me exactly how many euros a month I can set aside.
3. Flag the two or three items where I'm spending more than I should, with a concrete action to cut them.
4. Propose a realistic savings target at 6 and 12 months.
Reply with a table and then a short comment.
- Check: you should get a table with three blocks (needs, wants, savings), the percentages and a precise monthly savings figure. If the numbers don't add up (the categories don't sum to your salary), paste this correction:
The totals don't match my net salary. Recheck the math line by line and redo the table.
- Refine with a second request. Ready-to-paste examples:
Replace the 50/30/20 method with the Kakebo and redo the table.
The €150 leisure is too much: redo the plan for me with a €80 cap and tell me where I move the difference.
- Transfer the result into a spreadsheet so you don't start over every month. Ask:
Turn this budget into a table I can copy into Google Sheets or Excel, with a "planned" column and an "actual" column to fill in.
You paste the result into the spreadsheet and each month you update only the actual column.
A concrete example
Marco, €1,500 net a month, felt he was "not making it to the end of the month" without understanding why. He pasted the prompt above with his real numbers. ChatGPT split the expenses and highlighted two things: the €150 leisure and three overlapping streaming subscriptions for €35.
By cutting two subscriptions (−€20) and bringing leisure down to €100 (−€50), Marco freed up €70 a month. The target that came out of it: €70 × 12 = €840 emergency fund by year-end. Marco pays it in automatically on payday, before he can spend it. The problem wasn't earning little, but knowing where the money was going.
When it does NOT work (and how to fix it)
If the AI makes up or gets the numbers wrong
Language models sometimes get calculations wrong or round badly. Don't trust the total at a glance. Check that the sum of the categories equals your net salary and, if it doesn't, ask it to recheck line by line. For numbers that matter, copy the table into a spreadsheet where the software does the sums, not the AI.
If you don't want to share your financial data
Legitimate, and you don't need to hand it over. To make a budget you don't need any name, IBAN or identifying data: anonymous figures (salary, rent, groceries) are enough. ChatGPT works with bare numbers and zero personal information. If instead you use an app linked to your account, read first how it handles data and enable two-factor authentication.
If you run out of free ChatGPT messages
The free plan has an hourly cap. If you get stuck halfway, you have two options: wait for the reset (usually a few hours) or move to another free AI to finish. Google's Gemini has a generous free tier for this kind of request and handles the same prompt without changes. Alternatively, Anthropic's Claude in its free version handles budget tables and calculations well.
If the budget is perfect on paper but you don't stick to it
The written plan isn't enough: you need the end-of-month check. Once a month, paste your real expenses into ChatGPT with this request:
Here are my real expenses for this month: [paste the figures by category].
Compare them with my planned budget and tell me only where I overspent and by how much.
Five minutes that turn a static spreadsheet into a real check.
A tip from someone who actually uses it
Don't ask the AI to guess your expenses: give them to it yourself, even rough ones. The difference between a useless budget and one that works lies entirely in the quality of the numbers you put in. Spend an evening looking at your last two statements and note the real figures, even the embarrassing ones. Then let the AI organize them.
Frequently asked questions
Can ChatGPT connect to my bank account to read expenses on its own?
No, ChatGPT doesn't connect to accounts: you provide the numbers. For automatic reading of expenses you need dedicated apps like YNAB or Monarch, which read recurring expenses, manage bills and subscriptions and categorize transactions based on your habits.
Which budget method is best to ask the AI for?
For beginners, the 50/30/20 (50% needs, 30% wants, 20% savings) is the simplest to follow. It's not the only one: you can ask for the Kakebo, the 80/20 or the Envelope System. Try the 50/30/20 the first month and, if it doesn't fit your situation, ask the AI to redo it with another method.
Can I get a savings challenge if I have a low salary?
Yes, and it's one of the best uses. A prompt that works:
Propose a monthly savings challenge suited to someone with a low salary who wants to start. My net income is [amount].
The AI knows schemes like the €1-a-day challenge or the jars method and adapts them to your real income.
Do I really have to pay for an app to manage money well?
No, and that's the myth to bust. A paid app is only needed if you want full automation of tracking; an effective budget can be done for free too. The value isn't in the tool you pay for, but in the habit of looking at the numbers every month. Those who skip that check overspend even with the most expensive app installed; those who do it with pen and paper, or with ChatGPT free, actually set money aside.