How to Use This BOI Mortgage Calculator
This BOI mortgage calculator is designed to give you a quick estimate of monthly repayments, total interest cost, and how much you could save with overpayments. It mirrors the practical decision points many buyers in Ireland consider: purchase price, deposit size, interest rate, and loan term.
While it is not an official lending quote, it is a strong planning tool for first-time buyers, movers, and investors who want to compare scenarios before speaking with a lender or broker.
What the Calculator Estimates
- Loan amount: Property price minus deposit, plus any fees rolled into the mortgage.
- LTV (Loan-to-Value): A key factor for mortgage pricing and eligibility.
- Estimated monthly repayment: Based on a standard amortizing loan formula.
- Total repayment and total interest: Useful for long-term affordability planning.
- Overpayment impact: Shows potential time and interest savings if you pay extra monthly.
Input Guide (So Your Results Are Realistic)
1) Property Price
Enter the likely purchase price. If you are still searching, test a few values to see how your monthly cost changes at different price points.
2) Deposit
A larger deposit usually lowers your LTV and can reduce your rate. Make sure your deposit value is realistic after accounting for emergency savings and transaction costs.
3) Interest Rate
Use a rate that reflects the mortgage product you are considering (fixed or variable). Even a small rate change can significantly affect monthly repayments over 25–35 years.
4) Term Length
Longer terms lower monthly repayment but increase total interest. Shorter terms increase monthly pressure but typically reduce lifetime borrowing cost.
5) Monthly Overpayment
Optional overpayments can materially cut interest and shorten payoff time. This is particularly useful when rates are high or when your income increases.
Example Scenario
Suppose you buy a home for €350,000 with a €70,000 deposit at 4.15% over 30 years. Your estimated loan is €280,000. The calculator shows your monthly repayment and the total amount you may repay over the full term. Add a monthly overpayment (for example, €100–€300) and you can immediately see how many months you might save.
Key Mortgage Planning Tips
- Stress-test your budget at a higher rate (for example, +1% to +2%).
- Check if fixed-rate break fees may apply before planning aggressive overpayments.
- Account for insurance, maintenance, and local charges, not just the mortgage payment.
- Keep a cash buffer for unexpected expenses after closing.
- Review your mortgage annually to spot refinancing or switching opportunities.
Important Notes
This BOI mortgage calculator provides estimates for educational and planning purposes only. Actual repayments can vary based on lender policy, product type, underwriting decisions, fees, and timing of rate changes. Always verify figures with an approved mortgage advisor or direct lender quotation before making financial commitments.