Before the property search begins, the budget should be settled: how much property is realistically financeable with your income and equity? Our budget calculator derives the maximum loan from the affordable monthly payment, deducts the purchase costs of your federal state and shows the maximum purchase price — the number that lets you search with focus.
How to use this calculator
The calculator works in three steps: affordable payment, maximum loan, maximum purchase price.
- Step 1: Enter your monthly household net income and existing obligations (e.g. other loans, alimony).
- Step 2: Set the maximum share of income that should go into the payment — banks usually calculate with 35 to 40%.
- Step 3: Enter equity, interest rate and initial repayment rate.
- Step 4: Select your federal state and whether an agent commission applies — both determine the purchase costs deducted from the budget.
Understanding the results
From income to purchase price in traceable steps:
- Maximum monthly payment: your income share for the financing minus existing obligations.
- Maximum loan: the payment scaled up via the annuity formula from interest plus repayment rate.
- Purchase costs: your state's transfer tax plus notary, land register and, if applicable, agent — they are paid out of the budget but create no equivalent value.
- Maximum purchase price: loan plus equity, adjusted for the purchase costs — the realistic upper limit for your property search.
Why conservative budget planning is crucial
The biggest danger in property financing is a budget calculated too tightly. If the payment is set at the upper limit, there is no buffer for rate rises at refinancing, maintenance, utility back-payments or income interruptions. As a rule of thumb, the payment should remain affordable even after a rate increase of two percentage points. Also often underestimated: purchase costs of roughly 9 to 12% of the purchase price are sunk costs that should ideally be covered entirely from equity — banks are reluctant to finance them and charge significant rate premiums if they do. For buy-to-let investors there is one more point: rental income can increase the affordable payment, but banks only count it partially (70 to 80% is common).
Tips
- •Cover at least the purchase costs from equity — financings above 100% of the purchase price are expensive and rarely granted.
- •Stress-test the payment: does it remain affordable with two percentage points more interest at refinancing?
- •Beyond the loan payment there are running costs: building fees (Hausgeld), maintenance reserves and property tax also belong in the monthly budget.