MAKE YOUR NEXT MOVE WITH CONFIDENCE
How Mortgage Interest Rates Change Repayments
Use simple rate scenarios to see the effect on your monthly housing budget.
Ghar.ie editorial guide · Sources checked 27 September 2026
Change one input at a time
Keep the loan and term unchanged when comparing rates. Otherwise it becomes hard to tell whether a lower payment comes from cheaper interest or a longer repayment period. Start with the rate offered to you, then compare a lower and higher scenario.
A practical comparison
For a €300,000 loan over 30 years, the approximate payment is €1,265 at 3%, €1,432 at 4% and €1,610 at 5%. These are mathematical examples, not available offers. A one-point increase from 4% to 5% adds roughly €178 per month in this example, money that must come from elsewhere in the household budget.
Look beyond the first rate period
A repayment model that holds the rate constant for 30 years does not predict what happens after a shorter fixed period expires. Read the offer for the rate period and subsequent terms. Run a second scenario to understand your exposure, but use the lender’s actual schedule when assessing a specific product.
Do not confuse interest savings with switching savings
A lower rate can reduce interest, but a switching decision also involves fees, incentives and possible early repayment charges. This repayment tool does not calculate a switching break-even date. Use it for payment comparisons and gather the separate costs before deciding to change lenders.