Mortgage Repayment Calculator (UK)
UK monthly mortgage payment — repayment vs interest-only side by side, fixed-term roll-offs and SVR risk.
Formula
Disclaimer: Excludes arrangement/valuation fees and assumes a constant rate for the term — UK reality reprices at each deal roll-off. Not financial advice.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Need mortgage repayment calculator results fast? Skip the spreadsheet and get a clear, defensible answer in one step — free, private and instant, recalculating live as you change any input.
About Mortgage Repayment Calculator (UK)
UK mortgages live in two-to-five-year chapters: you fix (or track) for a deal period, then roll onto the lender's Standard Variable Rate unless you remortgage — so the rate you enter here is this chapter's rate, and the remortgage date is your most important diary entry. The defaults (£220,000 at 4.7% over 25 years) show both repayment styles side by side. Repayment (capital + interest) is the modern default and the only structure that guarantees you own the house at term end. Interest-only's seductive lower monthly — about £860 versus £1,250 at the defaults — comes with the full £220,000 still owed at maturity, which is why FCA rules demand a credible repayment vehicle (investments, sale of another property; 'hope' does not qualify) before lenders offer it to residential borrowers. Strategy at every roll-off: start remortgage shopping ~6 months out (offers last that long), compare the new deal's TRUE cost including arrangement fees (a £999 fee on a 2-year fix adds ~0.2% effective on this balance), and check your new LTV band — slipping under 75% or 60% unlocks visibly cheaper pricing. Most fixes allow 10% annual overpayments penalty-free; used fully, that quietly compresses a 25-year term toward 19–20.
How to use Mortgage Repayment Calculator (UK)
- 1Enter Mortgage amount, Interest rate (%), Term (years) into the Mortgage Repayment Calculator.
- 2The result is computed automatically using Repayment = amortization formula ; Interest-only = balance × rate ÷ 12 (principal never falls) — there is no button to press; it updates live as you type.
- 3Change any input to model a different scenario, then use “Copy result link” to share the exact numbers.
Why use Mortgage Repayment Calculator (UK)?
- ✓Computes mortgage repayment calculator instantly with the correct formula — no spreadsheet needed
- ✓100% free and unlimited, with no sign-up, login or paywall
- ✓Runs entirely in your browser, so the figures you enter are never uploaded or stored
- ✓Shows the formula, a live worked example and references so you can defend the number
Frequently asked questions
What happens when my fixed rate ends?+
You move to the lender's SVR — historically 2–4% above decent fixed deals — unless you remortgage or product-transfer. On the default balance that's hundreds a month of drift. Set a reminder 6 months before expiry; a same-lender product transfer takes days if a full remortgage feels heavy.
Can I get an interest-only mortgage on my home?+
Only with an FCA-acceptable repayment strategy evidenced upfront — significant equity, investment vehicles, or sale-of-property plans — and usually at lower LTVs (50–75%). Buy-to-let is different: interest-only remains standard there because the rental business model and eventual sale are the vehicle.
How much can I overpay without penalty?+
Most fixed deals: 10% of the outstanding balance per year before Early Repayment Charges (1–5%, typically stepping down through the fix) apply. Trackers and SVR often allow unlimited overpayment. The 10% allowance on the default loan is £22,000/year — far more than most can use, so the cap rarely binds in practice.
Is a longer term a way to beat affordability checks?+
Lenders increasingly write 30–40 year terms to pass affordability, and you can overpay later to compress it. The danger is drift: a 40-year term taken at 35 runs past retirement, which lenders test against pension income. Take the term you need for safety, then behave like it's five years shorter.
Related Finance tools
Human Life Value (HLV) Calculator
The economic value of your future earnings to your family — the income-replacement basis for sizing a life-insurance cover.
● LiveTerm Life Insurance Coverage Calculator
How much term-life cover you actually need — replacing income, clearing debts and funding goals, net of existing assets and cover.
● LiveDIME Method Life Insurance Calculator
The DIME formula — Debt + Income + Mortgage + Education — a fast, complete way to size a life-insurance cover.
● Live