Finance · Real Estate 6 min read

Loan Simulator: See the True Cost of Borrowing Before You Sign

Most borrowers focus on the monthly payment and ignore the total cost. A $300K mortgage at 7% over 30 years costs $719K in total, more than double the loan amount. Here is how to plan smarter.

Key Insights

Key takeaways Total interest often exceeds principal. A $300K mortgage at 7% over 30 years adds $419K in interest payments.
15-year vs 30-year matters hugely. Shorter terms have higher monthly payments but save tens of thousands in interest.
Even 0.5% rate difference on a $300K loan means $30K+ more or less paid over the life of the loan.
Extra payments work wonders. Adding $200/month to a 30-year mortgage can shave 8 years off the term.
Credit score impacts rates. A 100-point difference can mean 1-2% rate change, saving six figures on a mortgage.

Key Metrics

MetricValueContext
$300K mortgage at 7% (30yr)$719K total$419K in interest
Same loan at 6%$647K totalSaves $72K vs 7%
15-year at 6.5%$468K totalSaves $251K vs 30yr
Extra $200/month-8 yearsShaves term from 30 to 22
Avg US mortgage rate 2026~6.8%30-year fixed
Avg new car loan~7.5%72-month term
Avg credit card APR~24%Most expensive borrowing

After two years of rising rates that froze the French property market, 2025 brought relief. The Banque de France reports average mortgage rates settling at 3.5% in early 2026, down from a peak of roughly 4.2% in late 2023. For buyers who paused their projects, the window is reopening.

But how much can you actually borrow? The answer depends on three things: your income, your existing debt, and a rule you may not have heard of: the HCSF cap.

The 35% rule that governs French mortgages

In 2022, the Haut Conseil de Stabilité Financière (HCSF) made binding what was previously advisory: French banks cannot extend mortgages where total monthly debt repayments exceed 35% of net monthly income. This includes all existing credit: car loans, consumer credit, everything.

It sounds simple but the implications are significant. On a €3,000/month net salary:

ScenarioMax monthly paymentBorrowing capacity (20y, 3.5%)
No existing debt€1,050€185,000
€200/mo car loan€850€150,000
€400/mo consumer credit€650€115,000

That €400/month in existing credit costs you €70,000 in borrowing capacity. Paying off consumer debt before applying for a mortgage is almost always mathematically worthwhile.

The real cost of waiting

Many buyers held off during the 2022-2024 rate spike. Here's what that decision cost: and what it saved: depending on timing:

📊 Rate impact on €300,000 loan over 20 years At 4.2% (2023 peak): monthly payment €1,849 · total interest €143,800

At 3.5% (2026): monthly payment €1,740 · total interest €117,600

Difference: €26,200 saved: just by waiting 2 years.

Of course, property prices also moved during that time. In many French cities, prices corrected 5-10% during the high-rate period. Buyers who waited may have benefited from both lower rates and lower prices.

How rates compare internationally

France's 3.5% looks attractive in a global context. American buyers face a structurally different market:

CountryAvg mortgage rate (2026)DTI limit
🇫🇷 France3.5%35% (HCSF binding)
🇩🇪 Germany3.8%~35-40%
🇬🇧 UK7.2%~4-4.5× income
🇺🇸 USA6.5%43-45%

A UK buyer taking the same loan as a French buyer pays nearly twice the interest over 20 years. The European Central Bank's rate policy, which France benefits from as a eurozone member, has been a significant structural advantage for French property buyers.

The hidden costs buyers forget

Your borrowing capacity calculation should never equal your purchasing budget. Banks lend on the property price: but you also need to account for:

On a €300,000 purchase, notary fees alone add €21,000-24,000. You need this in cash: banks don't finance fees. Combined with a minimum 10% down payment requirement from most banks, expect to need 18-23% of the purchase price in liquid savings before you can proceed.

Calculate your capacity before speaking to a bank

Knowing your borrowing capacity before entering a bank negotiation gives you a significant advantage. You can assess whether a property is realistic, compare scenarios (20y vs 25y loan, different rates), and understand exactly what income you need to afford the property you want.

The WealthRank Lending Simulator lets you model all of this in seconds: including a "reverse" mode that tells you exactly how much you can borrow based on your income and existing debts.

Frequently asked questions

What is the maximum debt-to-income ratio for a French mortgage?

Since 2022, the HCSF binding rule caps total monthly debt repayments at 35% of net monthly income for French mortgages. This includes all existing debts: car loans, consumer credit, and any other credit obligations.

How much can I borrow on a salary of €3,000/month in France?

With no existing debt and a 20-year mortgage at 3.5%, the HCSF 35% rule limits your monthly payment to €1,050, giving you a borrowing capacity of approximately €185,000. Each €200/month in existing debt reduces this capacity by roughly €35,000.

What is the current mortgage rate in France in 2026?

As of early 2026, average French mortgage rates have settled at approximately 3.5%, down from a peak of 4.2% in late 2023, according to the Banque de France.

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