AI Prompt to Work Out What Your Loans Will Cost and Whether Refinancing Pays

What you need

Paste the snapshot template below with each loan's outstanding balance and current interest rate. Say in the line whether the rate is fixed, variable or interest-only, and for a fixed rate, until when.

Below the snapshot, add two lines:

• Remaining term and monthly payment for each loan: [loan name, time left, payment]
• Refinancing offer: [rate, fees, term and fixed period, or "none"]

The remaining term and payment are on your latest loan statement or in the lender's app. From balance, rate and term, the model can rebuild the payment and compare it with yours. A mismatch usually means fees or insurance are included in the payment, or that a figure was typed wrong.

For the refinancing line, include every cost the offer mentions: arrangement or processing fees, valuation, legal or notary costs, and any early repayment fee your current lender would charge. Whether an early repayment fee applies, and how large it can be, varies by country and by contract, so take the figure from your contract or ask your lender. If you have no offer yet, write "none". The model will still work out the total cost and explain how a refinancing decision is usually tested.

Here is my financial snapshot. Use only these numbers.

Currency: [e.g. EUR]
Date: [today's date]
Age: [optional]

ASSETS
[name] — [category: cash / stocks / ETFs / crypto / property / metals / other] — [value]
[name] — [category] — [value]
...

LIABILITIES
[name] — [type: mortgage / car loan / credit card / student loan / other] — [outstanding balance] — [interest rate if known]
...

CONTEXT (optional but improves the answer)
Monthly income after tax: [amount]
Monthly spending: [amount]
Amount I add to savings or investments each month: [amount]
Value of the same assets 12 months ago: [amount]

The prompt

Copy this exact text and paste it into ChatGPT, Claude or Gemini directly beneath your snapshot block.

You are a financial educator who explains loans and mortgages in plain language.
Using only my snapshot above, plus the lines below, review the loans I already
have.

Remaining term and monthly payment for each loan: [loan name, time left, payment]
Refinancing offer: [rate, fees, term and fixed period, or "none"]

1. For each loan, explain how its type works (fixed, variable or interest-only)
   and what that means for my payments.
2. Calculate the total I will still pay on each loan and how much of it is
   interest. Check the result against my monthly payment and flag any mismatch.
3. If I gave a refinancing offer, compare the monthly payments, add up all fees,
   and show how many months the saving takes to cover them. Say what happens
   when the new fixed period ends.
4. Explain the usual refinancing process and the costs people often overlook.
5. List questions I could ask my current lender before deciding, including what
   my contract allows on extra repayments, early repayment and rate changes.

Show the calculations. If a number is missing, ask me for it instead of
estimating. Name no lenders or products, suggest no target rate and give no
recommendation to refinance or stay. Say where the rules depend on my country.

What good output looks like

The answer should treat each loan separately and show the formula it used, so you can rerun it in a spreadsheet.

Say you have a 200,000 EUR mortgage at 4.8% with 20 years left. The monthly payment works out at about 1,298 EUR, so the remaining 240 payments add up to about 311,500 EUR, of which about 111,500 EUR is interest. If your statement shows a higher payment, the model should ask what else is in it.

The refinancing test needs every number on the page. An offer at 4.1% over the same term brings the payment to about 1,223 EUR, a saving of about 75 EUR a month. With 2,500 EUR of fees, the saving covers them after about 33 months. A good answer then asks about the new fixed period: if it lasts three years, the saving has only just paid for itself when the rate is reset.

A second loan gets the same treatment in its own currency. A car loan of 300,000 CZK at 8.9% over five years comes to about 6,213 CZK a month and about 72,800 CZK of interest.

The lender questions should fit your contracts, for example whether extra repayments are allowed, what fee, if any, applies to repaying early, and how a new rate is set when a fixed period ends.

What this can't tell you

The calculations assume a standard repayment loan with the rate unchanged for the term you give. Real contracts add fees, insurance and rate resets, so your lender's figures are the reference.

The model has no live view of market rates, so any rate it calls typical may be out of date. It also cannot tell you whether a lender will offer you a better rate, which depends on your income, credit record and the property's value at the time. Early repayment fees, notice periods and your rights at the end of a fixed period vary by country, and the model may present one country's practice as general. The tax treatment of mortgage interest also differs by country. Check the payment formulas, since models often slip when compounding over long terms.

Doing this without the retyping

Sumio includes this as "Loans and Mortgages Guidance", one of the 62 prompts in the app. It runs on your total liabilities, so the loans and mortgages you already track there go into the analysis without copying a single balance by hand. Your records are stored on your device, and running the prompt sends the figures it needs to an AI provider to produce the answer. The AI assistant is part of Sumio Premium.