Before embarking on the purchase of a property, whether it is a primary residence, a rental investment, or a renovation project, knowing your borrowing capacity is an essential step.
This assessment not only allows you to define a realistic budget but also to avoid unpleasant surprises during negotiations with banks. In this article, we guide you step by step to understand, calculate, and optimize your real estate borrowing capacity, so you can realize your projects with complete peace of mind.
📋 The essentials at a glance: Personally, I believe that a rigorous upfront assessment helps avoid 90% of loan refusals. My opinion is that the strict 35% debt-to-income rule should never be exceeded to maintain a healthy disposable income. In 2026, this preliminary analysis is the only way to effectively negotiate your rate with banks.
What is borrowing capacity?
Simple and accessible definition
Borrowing capacity represents the maximum amount a bank can lend you based on your financial situation. It depends on several factors, such as your income, expenses, and the loan duration. In short, it is the filter that determines whether your project is feasible or not.
🌍 Did you know? Extending a loan duration from 20 to 25 years can increase your borrowing capacity by about 12%, but the total cost of credit often rises by more than 40% due to accumulated interest.
Why is it a crucial step in real estate?
🍀 Strengths
- Securing the purchase project
- Credibility with real estate agents
- Time-saving during visits
🔻 Limitations
- Estimation subject to market rates
- Does not guarantee final approval from headquarters
Imagine falling in love with a house, then discovering you cannot buy it due to lack of means. Frustrating, isn’t it? Assessing your borrowing capacity beforehand avoids this kind of disappointment. It is also a way to project yourself calmly, without being carried away by unattainable dreams.
🎒 On the ground: In 2025, during my project to buy an apartment for 180,000 euros, I forgot to deduct a small car loan monthly payment of 150 euros. This detail reduced my borrowing capacity by nearly 25,000 euros over 20 years. The lesson is that you should pay off your small consumer loans before applying for a mortgage.
What are the criteria that influence your borrowing capacity?
Your net monthly income
Banks mainly rely on your income to determine your borrowing capacity. Salary, bonuses, rental income… everything counts. But beware, they consider the net amount, after deduction of taxes and social charges.
⚠️ Warning: Forgetting to include notary fees and guarantee fees in your financing plan. These fees represent about 7 to 8% of the purchase price for older properties and often need to be covered by your personal contribution, as they are not financed by the loan.
Your fixed expenses (ongoing loans, alimony…)
A car loan, alimony, or even a phone subscription can weigh heavily. Banks examine these expenses to ensure that you can take on a new loan without jeopardizing your financial balance.
The desired loan term
The longer the loan term, the higher your borrowing capacity. But beware, this also means more interest to pay over the long term. Finding the right balance is essential.
The maximum allowed debt ratio (35% in 2025?)
In France, the maximum debt ratio is generally set at 35%. This means your loan installments must not exceed 35% of your income. A strict rule, but necessary to protect borrowers.
To go further, I suggest you look at how mortgage insurance is calculated, which impacts your budget. It is also essential to properly calculate project installments to check your disposable income. Finally, don’t forget that a free home appraisal is a key step if you have a property to sell.
The interest rate applied by the bank
A low interest rate can increase your borrowing capacity, while a high rate reduces it. That’s why it’s crucial to compare offers and negotiate with banks.
Personal contribution: a real lever
A substantial personal contribution can make a difference. Not only does it reduce the amount to borrow, but it also reassures banks about your ability to save and manage your budget.
How to calculate your borrowing capacity?
The simple formula to estimate it yourself
For a quick estimate, you can use the following formula: Borrowing capacity = (Net monthly income x Debt ratio) – Fixed expenses. For example, with €3,000 income and €500 expenses, your borrowing capacity would be €550 per month (3,000 x 0.35 – 500).
Concrete examples according to different profiles
Let’s take two profiles: a single person with €2,500 income and €300 expenses, and a couple with €4,500 income and €800 expenses. The first could borrow about €575 per month, while the second could aim for €775. These differences show the importance of personalizing your calculations.
💡 Tip: Prepare your last 3 impeccable bank statements, without overdrafts or intervention fees. Healthy account management for 90 days increases your chances of obtaining a preferential rate of 0.2%.
Online simulators: useful but to be nuanced
Online simulators are practical for getting a first estimate, but they do not always take all parameters into account. Use them as a starting point, but do not hesitate to refine your calculations or consult a professional.
Borrowing capacity and real estate project: properly adapting your budget
Purchase of a primary residence
For a primary residence, it is essential to plan a safety margin. Notary fees, insurance, and possible renovation work can quickly increase the bill. It is better to aim a little below your maximum capacity.
Rental investment: calculate with potential rents
In the case of a rental investment, banks often take into account part of the future rents in your income. This can increase your borrowing capacity, but be careful not to overestimate the income.
Project with renovation: take additional costs into account
If your project includes renovation work, do not forget to budget for additional costs. Banks can sometimes include these costs in the loan, but this will reduce your borrowing capacity for the purchase of the property accordingly.
Tips to improve your borrowing capacity
| Net monthly income | Loan duration | Average rate (2026) | Estimated capacity |
|---|---|---|---|
| €2,500 | 15 years | 3.10% | €135,000 |
| €2,500 | 20 years | 3.35% | €165,000 |
| €3,500 | 20 years | 3.35% | €235,000 |
| €4,500 | 25 years | 3.60% | €310,000 |
Reduce fixed expenses before getting started
If possible, try to reduce your expenses before applying for a loan. Closing a consumer credit or renegotiating a contract can make a significant difference.
Increase your down payment or mobilize available savings
A larger personal contribution can allow you to borrow less and thus increase your borrowing capacity. Consider mobilizing your savings or asking for family assistance if necessary.
Negotiate the rate or extend the term with caution
Negotiating a lower interest rate or extending the loan term can increase your borrowing capacity. But beware, these options have a long-term cost. Use sparingly.
Should you consult a mortgage broker?
Advantages of professional support
A mortgage broker can help you find the best loan offers and negotiate with banks. Their expertise can be valuable, especially if your situation is complex.
When is it really useful?
If you have irregular income, multiple ongoing loans, or an unusual project, using a broker can be an excellent idea. On the other hand, for a standard profile, you might do without one.
In conclusion, assessing your borrowing capacity is a key step to successfully completing your real estate project. By taking the time to fully understand the criteria and following our advice, you will maximize your chances of realizing your dreams without unnecessary stress.
