Breaking a fixed-rate mortgage early usually means an Early Repayment Charge (ERC) — but if rates have dropped enough since you fixed, switching can still work out ahead. This estimates the fee using the same simplified formula Irish lenders publish, and compares it against the interest you'd actually save.
Lenders calculate the Early Repayment Charge as your outstanding balance × the difference between your locked-in rate and a comparable market rate today × the years left on your fixed term — this is the published methodology (e.g. ICS Mortgages' regulatory disclosure), not an estimate invented for this calculator. If today's rate is higher than yours, the fee is zero — lenders only charge for their own funding loss, never the other way round. Your actual quote will very likely be lower than this figure, since lenders also credit the loan's reducing balance, payment timing, and any unused overpayment allowance. Interest saved is then worked out by running the standard mortgage amortisation at your current rate and at the new rate over the same remaining period, and the difference is compared against the fee.
No — treat it as an upper-bound estimate. Lenders use the same basic formula (balance × rate difference × time remaining) but the actual figure gets credit for the loan's reducing balance since you fixed, the timing of payment, any unused annual overpayment allowance, and any cap on the charge. Ask your lender for an exact figure before deciding.
Lenders technically use a wholesale swap rate you don't have access to. The best available stand-in is a fixed rate a lender is actually advertising today for a term similar to what's left on yours — close enough for an estimate, since it's the same approximation every consumer-facing break-fee tool has to make.
Lenders only charge an Early Repayment Charge to recover their own funding loss. If market rates have risen since you fixed — meaning the lender can now re-lend your balance at a better rate than they were locked into — there's no loss to recover, so no fee applies.
That's the one period both scenarios are actually rate-certain for — you'd keep paying your locked-in rate either way, or the new rate you switched to. What happens to either mortgage after that is speculation regardless of whether you switch, so comparing further out would just be adding assumptions this calculator can't know.
Counter-intuitively, no — a bigger drop tends to make the numbers look worse, not better. The break fee scales exactly linearly with the rate difference (balance × difference × years), while the interest you actually save grows more slowly than that as the difference widens, since the mortgage payment itself is a non-linear function of the rate. The fee pulls further ahead the bigger the gap, which is part of why this calculator will show breaking as not worth it in most realistic scenarios using the published formula — your actual bank-quoted fee, after their own credits and caps, is the number that can flip that.
Figures are estimates for informational purposes only, based on the assumptions you enter, and are not tax advice. Consult a tax advisor or Revenue.ie before making financial decisions.