Remortgage Savings Calculator
Compare your current mortgage with a possible new deal. Enter your numbers below to estimate monthly payments, interest costs, and whether switching could be worthwhile.
How to use this remortgage calculator
A remortgage calculator helps you compare two scenarios: staying on your current mortgage versus switching to a new deal. This page focuses on the practical numbers most homeowners care about: monthly payment, total interest, upfront costs, and how long it takes to recover fees.
Start with your current outstanding balance, not the original loan amount. Then enter your current rate and term remaining. For the remortgage option, add the new rate and term you are considering. Finally, include fees and any early repayment charge. The calculator will estimate whether the switch lowers your monthly payment and whether it saves money overall.
What remortgaging means
Remortgaging means replacing your existing mortgage with a new mortgage, either with your current lender or a different lender. People usually remortgage for one of these reasons:
- To move from a higher rate to a lower fixed or tracker rate.
- To avoid rolling onto a lender’s standard variable rate after an introductory deal ends.
- To change the term and reduce monthly payment pressure.
- To borrow additional funds for home improvements, debt consolidation, or other goals.
The key point: lower monthly payments do not always mean lower lifetime cost. Term length and fees matter.
Inputs explained (and why they matter)
Outstanding balance
This is the capital you still owe. Payment and interest calculations are built from this number, so keeping it accurate is essential.
Current and new rates
Even small rate differences can have a large impact over many years. A 0.5% drop can be meaningful on a large balance.
Current remaining term and new term
Extending your term often reduces monthly payments, but usually increases total interest. Shortening your term does the opposite: higher monthly payment but lower long-term interest.
Fees and early repayment charges
Product fees, legal fees, valuation costs, broker fees, and exit penalties can significantly change the result. That is why this calculator includes a break-even estimate.
Costs people often forget
- Arrangement fee: charged by many lenders for a new mortgage product.
- Valuation and legal costs: sometimes free with a product, sometimes not.
- Early repayment charge (ERC): applies if you leave your current deal during a penalty period.
- Broker fee: if using an adviser who charges directly.
- Higher total interest from term extension: not an upfront fee, but a real long-term cost.
Interpreting your result correctly
The calculator gives you both monthly and lifetime perspectives:
- Monthly payment change: useful for cash-flow planning.
- Total interest comparison: shows long-term borrowing cost.
- Net lifetime impact after fees: gives a more realistic decision metric.
- Break-even point: tells you how long you may need to stay in the new deal to recover costs.
If you expect to move house or refinance again soon, break-even timing becomes especially important.
When remortgaging tends to make sense
1) Your current deal is ending soon
Many borrowers see a jump in payment if they fall onto a standard variable rate. Comparing offers in advance can prevent that.
2) You can get a better rate at your loan-to-value band
As your property value rises or your balance falls, your loan-to-value (LTV) improves. Better LTV bands often unlock better rates.
3) The fee-to-savings ratio is favorable
A deal with slightly higher rate but low fees can beat a lower-rate deal with heavy fees, especially for smaller balances or short stays.
Simple strategy before applying
- Check your current lender’s product transfer options.
- Compare at least 3–5 products across different fee structures.
- Run scenarios with the same term and with a shorter term.
- Stress-test affordability in case rates rise later.
- Confirm whether any ERC still applies on your existing mortgage.
Important reminder
This remortgage calculator is for education and quick planning. It does not include every underwriting detail, changing variable rates, overpayments, or all lender criteria. Before making a final decision, verify figures with a qualified mortgage adviser or lender illustration.