Mortgage Repayment Calculator
Calculate your monthly mortgage repayments for any loan amount, interest rate, and term. Our calculator uses the standard annuity formula used by Irish banks and gives you a full breakdown of total interest paid over the lifetime of your mortgage.
Key terms
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Loan-to-Value (LTV)
The ratio of a mortgage loan to the property's value, expressed as a percentage — the headline metric for how much equity a buyer has and what rate they can get.
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Loan-to-Income (LTI)
The ratio of a mortgage loan to the borrower's gross annual income — the Central Bank caps this at 4× for most Irish buyers.
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Mortgage Stress Test
The Central Bank requirement that lenders assess affordability at an interest rate at least 2 percentage points above the offer rate before approving a mortgage.
How is this calculated?
Monthly repayments are calculated using the standard annuity (PMT) formula: M = P × [r(1+r)ⁿ] / [(1+r)ⁿ - 1], where P is the principal (loan amount), r is the monthly interest rate (annual rate ÷ 12), and n is the number of monthly payments. This is the same formula used by Irish mortgage lenders. All calculations assume a repayment mortgage (capital and interest), not an interest-only mortgage.
The rate a borrower is actually offered depends on the LTV tier they fall into — most Irish lenders price sub-60%, 60–80%, and 80–90% LTV tiers separately. Whether the loan is approvable at all depends on the LTI cap (4× for first-time buyers, 3.5× for SSBs) and on passing the mortgage stress test.
Frequently Asked Questions
How are mortgage repayments calculated in Ireland?
Irish mortgage repayments are calculated using the annuity formula. Each monthly payment covers the interest due on the outstanding balance plus a portion of the principal. In the early years, most of your payment goes to interest. As the loan is paid down, more of each payment reduces the principal.
What is the average mortgage interest rate in Ireland in 2026?
As of 2026, the average variable mortgage rate in Ireland is approximately 3.5%–4.5%, though rates vary significantly by lender, loan-to-value ratio, and whether you opt for a fixed or variable rate. Fixed rates are currently available from around 3.2% for short-term fixed periods.
Can I overpay my mortgage in Ireland?
Yes, most Irish mortgages allow overpayments, though some fixed-rate mortgages restrict the amount you can overpay without incurring a breakage fee. Overpaying reduces your outstanding balance faster, saving you interest over the term. Use our Mortgage Overpayment Calculator to see the impact.
How much does a €300,000 mortgage cost per month?
At a 4% interest rate over 30 years, a €300,000 mortgage costs approximately €1,432 per month. Over 25 years at the same rate, it would be approximately €1,581 per month. The total interest paid over 30 years would be approximately €215,600.
What is LTV and does it affect my mortgage rate?
LTV (Loan-to-Value) is the size of your mortgage as a percentage of the property value. A lower LTV typically means a lower interest rate because the lender faces less risk. In Ireland, first-time buyers can borrow up to 90% LTV, while second-time buyers are limited to 80% LTV under Central Bank rules.
Last updated: January 2026 · Rates sourced from Revenue