Swiss banking rules: 33% rule, imputed interest 5%, equity check
Buying property in Switzerland involves some of the strictest mortgage affordability checks in the world. Before any Swiss bank approves a home loan, it applies standardized rules to verify that you can sustain the financial burden long-term. Our free Swiss Mortgage Affordability Calculator lets you perform this check yourself in seconds, using the same criteria Swiss banks apply.
Swiss banks follow a clear framework when assessing mortgage applications. The key principle is the affordability ratio: the total annual housing costs must not exceed 33% of gross household income. This rule applies regardless of current market interest rates and is designed to protect both borrowers and lenders from financial stress in case rates rise.
Our affordability calculator is straightforward to use. Simply enter:
The tool instantly calculates the required mortgage, applies the 5% imputed interest rate, adds amortization and maintenance costs, and checks whether the result stays within the 33% threshold. It also verifies whether your equity meets the minimum 20% requirement.
One of the defining features of Swiss mortgage law is the mandatory minimum equity contribution:
For a property priced at CHF 700,000, this means you need a minimum of CHF 140,000 equity, of which at least CHF 70,000 must be hard equity.
Consider a couple looking to buy an apartment in Geneva for CHF 850,000. Their combined gross annual income is CHF 160,000, and they have CHF 180,000 in savings.
Since the ratio is below 33%, the mortgage would be considered affordable under Swiss banking standards. Our calculator delivers this analysis instantly.
Many prospective buyers are puzzled when they discover that Swiss banks use a 5% interest rate for affordability calculations when actual rates may be closer to 1–2%. The reason is long-term prudence. Swiss mortgage rates have historically been much higher – reaching 7% or more in the 1990s. The imputed rate is not a prediction; it's a safety buffer that prevents households from becoming over-indebted if rates normalize.
This tool is valuable for a wide range of users:
While our calculator reflects standard Swiss banking guidelines, individual cases may vary. Self-employed applicants, non-residents, or buyers of atypical properties (e.g., vacation homes) may face additional scrutiny. We recommend using this tool as a first-pass filter, then consulting a mortgage advisor or your bank for a formal pre-approval.
The 5% imputed rate is a stress-test standard used across Swiss banking. It ensures that borrowers remain solvent even if mortgage rates rise substantially. It is not the rate you will actually pay.
If the affordability check fails, banks will typically decline the mortgage or impose restrictive conditions. Solutions include increasing your down payment, choosing a less expensive property, or adding a co-borrower with additional income.
For investment properties, rental income is generally factored in, but banks typically apply a conservative discount (often 20–30%) to account for vacancy risk. The calculator focuses on primary residential properties.
Yes, up to 10% of the purchase price can come from an early withdrawal of your occupational pension (2nd pillar). However, this reduces your retirement savings and the amount should ideally be repaid over time.
The 33% threshold is an industry standard widely applied by FINMA-regulated banks and insurers. Some cantonal banks or specialty lenders may apply slightly different criteria, but the 5% imputed rate and 20% equity rule are near-universal.