Mortgage instalment calculator
Enter your own parameters - the result updates immediately.
Fixed for the whole term. This is not the APRC.
The starting values are an example to edit, not a current market offer.
Result
- Loan amount
- Amount received
- Total interest
- Fees (commission and other costs)
- Cost of credit (interest + fees)
- Sum of instalments
- Total to repay (principal + cost)
Assumptions used
- Insurance, periodic fees and rate changes are not included. This is a simulation, not a bank offer.
- The simulation assumes a fixed rate for the whole term. Over many years the real instalment may differ. The result is not a creditworthiness assessment or a guarantee of getting a loan.
| No. | Instalment | Principal | Interest | Balance after |
|---|---|---|---|---|
What if the rate were different?
Comparison at a fixed rate for the whole term, calculated from the first month. These are scenarios, not forecasts.
| Rate | First instalment | Instalment difference | Cost of credit (interest + fees) | Cost difference | |
|---|---|---|---|---|---|
What next?
The calculator works out a hypothetical scenario from your own parameters. See real offers and their terms in the comparison, and the editorial order of offers in the ranking.
How to use the mortgage instalment calculator
What you can set
You enter the loan amount, the term (in years or months), the nominal interest rate per year and the instalment type: equal or decreasing. Under the extra options you can add a commission. The starting values are an example, not a bank offer.
A fixed rate in the simulation versus reality
The calculator assumes the same rate for the whole term. On a loan lasting many years the rate usually changes, so the real instalment may be different. A mortgage rate is usually made up of the bank's margin plus a reference rate; you enter the total nominal annual rate, as the bank shows it in its illustration.
Loan amount and down payment
Enter the amount you are applying for at the bank: the property price minus your down payment (plus any costs the bank lets you finance with the loan). With a 20% down payment on a property worth 500,000, you enter 400,000.
Loan term
The longer the term, the lower the instalment but the higher the cost of credit, because interest accrues for more years. For 400,000 at 7.5% the instalment falls from 3,222.37 (20 years) to 2,796.86 (30 years), about 13% lower, while total interest rises from about 373,000 to about 607,000.
Rate change scenarios
Below the result you will see a table: the base rate, +1 pp, +2 pp and, optionally, your own rate. For each we show the instalment, its difference from the base instalment, the cost of credit and its difference. All variants are calculated from the first month for the whole term, so this is a comparison and not a forecast of instalments in later years.
Worked example
A loan of 400,000 at a nominal rate of 7.5% a year, over 25 years (300 instalments), equal instalments, no commission. The calculator shows an instalment of 2,955.96, a sum of instalments of 886,792.23 and total interest of 486,792.23. The formula without rounding the instalments gives total interest of 486,789.41; the difference of about 3 comes from rounding the instalments to the cent over 300 months. At a rate of 9.5% the instalment is 3,494.79.
What the calculator does not include
We don't include property insurance, bridging insurance, commission (other than the one you enter) or a variable interest rate. The result is not an assessment of your creditworthiness or a guarantee of getting a loan. To compare the full cost of credit, use the APRC in the bank's illustration.
How is this calculated?
The same engine as the personal loan instalment calculator: identical inputs give an identical schedule. Equal instalments use the annuity formula; decreasing instalments have a constant principal part. You can enter the term in years or months; internally it is converted to months.
The higher-rate scenarios (+1 and +2 percentage points, and your own rate) are calculated from the first month for the same amount and term. This is a comparison, not a forecast: we don't model the rate changing during the loan. We don't include insurance, commission other than the one you enter yourself, or your creditworthiness.