LTV Band Overpayment Calculator
Should you put a lump sum on your mortgage or in a savings account? When the payment moves you into a cheaper LTV band at remortgage, the cheaper rate applies to your whole remaining balance, not just the lump sum.
Learn how this calculator works →Calculator inputs
Personal Savings Allowance applied automatically (£1,000 basic / £500 higher / £0 additional).
What happens to my data?
Pay the lump sum
£5,500
net benefit over the 5-year fix
Annualised return on lump sum
1.77%
Band jump
85% LTV → 75% LTV
Rate: 4.80% → 4.30% (0.50 pp saving)
Monthly payment delta
£399
per month freed up by paying the lump sum
Savings pot at fix end
£75,986
Effective savings rate
4.73%
after PSA + your marginal rate
Important: BoE band rates are sector averages. Your actual offer will vary by lender, credit profile, and the day you apply. Use the "Override BoE rates" panel to plug in real quotes from a comparison site or broker.
Net wealth across the 5-year fix
Year-by-year breakdown
| Year | Net A (pay) | Net B (save) | Difference |
|---|---|---|---|
| 1 | -£185,640 | -£186,686 | +£1,046 |
| 2 | -£175,847 | -£177,966 | +£2,119 |
| 3 | -£165,601 | -£168,820 | +£3,219 |
| 4 | -£154,882 | -£159,227 | +£4,346 |
| 5 | -£143,666 | -£149,166 | +£5,500 |
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Important: Not Financial Advice
This calculator is provided for educational and illustrative purposes only. Freedom Isn't Free is not authorised or regulated by the Financial Conduct Authority (FCA) and does not provide financial advice, investment recommendations, or tax guidance.
The projections shown are hypothetical, assume a constant rate of return, and do not account for inflation, taxes, or fees. Actual investment returns vary and you may get back less than you invest. Past performance is not a reliable indicator of future results.
Before making any financial decisions, please consult with an independent financial adviser regulated by the FCA. For help finding an adviser, visit MoneyHelper or Unbiased.
Where links to financial products appear on this page, some may be affiliate links. See our full disclaimer for details.
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