+£50 per month
- Initial planned monthly budget
- £1,384.00
- Projected payoff time
- 23 yr 5 mo
- Interest saved versus current plan
- £11,712.50
Charges and lender allowances are excluded. Home costs can continue after payoff.
Home financing
UK mortgage repayment calculator
Explore the monthly repayment, the end of an initial deal and the difference overpayments could make. Keep your fees and home budget in view, in pounds.
Calculated in your browser. No account or email needed.
Capital-repayment planning in equal monthly periods, with an optional assumed follow-on rate. Daily interest and lender-specific recalculations can produce different payments. Rates are illustrative; early-repayment charges, affordability and regional purchase taxes are not calculated.
Your home purchase
UK / repaymentIllustrative contract rate, not a current offer or APRC.
After the initial deal
The initial deal is part of the full repayment term. With this option off, the initial rate lasts for the whole projection. Neither assumption predicts a lender’s future rate.
Used only when the follow-on option is enabled; shorter than the full repayment term.
Used only when enabled. Starts the month after the deal ends, then stays constant. The payment is recalculated over the remaining original term.
Overpayments
After the regular payment. Overpayments are capped at debt owing. Lender allowances and early-repayment charges are not calculated.
Fees and home costs
Added once at the start and earns interest. Exclude it from cash-paid costs.
Enter quoted fees and applicable SDLT, LBTT or LTT once. Exclude your deposit, financed fee and recurring costs. No regional tax is inferred.
Your fixed allowance for council tax or NI domestic rates, insurance, service charges and other costs. Zero omits them.
Your monthly picture
AssumptionsInitial monthly repayment before overpayments
Equal monthly periods / GBP£1,334.00 GBP
DollarMath provides calculators and information for educational purposes. It does not provide financial advice. Read the disclaimer.
Initial planned monthly budget£1,334.00Includes recurring overpayment and entered home costs
Starting mortgage balance£240,00080.00% modelled loan-to-value, including financed fee
Projected payoff time25 yr300 monthly payments
The 4.5% initial rate is held for the entire projection. Enable a follow-on rate to explore the end of a shorter deal. Daily interest, lender payment recalculations and early-repayment charges can change actual results.
- Product fee financed
- £0.00
- Applied one-off overpayment
- £0.00
- Projected mortgage interest
- £160,198.96
- Interest saved with overpayments
- £0.00
- Deposit + entered cash purchase costs
- £60,000.00
Your path to paid off
Mortgage balance (GBP)Current planWithout overpayments
What could a little extra change?
Add to your monthly overpayment while keeping the rate assumptions, fees, home costs and one-off payment unchanged.
+£100 per month
- Initial planned monthly budget
- £1,434.00
- Projected payoff time
- 22 yr
- Interest saved versus current plan
- £21,745.86
Charges and lender allowances are excluded. Home costs can continue after payoff.
+£200 per month
- Initial planned monthly budget
- £1,534.00
- Projected payoff time
- 19 yr 9 mo
- Interest saved versus current plan
- £38,076.22
Charges and lender allowances are excluded. Home costs can continue after payoff.
These are illustrations, not recommendations. Trying an option updates your current inputs and results. Saved comparisons are kept.
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The longer view
Mortgage payments through payoff total £400,198.96, including the financed fee once. Entered home costs over that horizon total £0.00. With deposit and cash-paid purchase costs, modelled cash through payoff totals £460,198.96. Home costs can continue afterward; a shorter horizon does not establish lifetime ownership savings. These are not settlement figures or a home valuation.
Year-by-year repayments and home budget
| Year | Months | Capital repaid | Interest | Other home costs | Combined budget | Debt remaining |
|---|---|---|---|---|---|---|
| 1 | 12 | £5,316.77 | £10,691.23 | £0.00 | £16,008.00 | £234,683.23 |
| 2 | 12 | £5,561.03 | £10,446.97 | £0.00 | £16,008.00 | £229,122.20 |
| 3 | 12 | £5,816.49 | £10,191.51 | £0.00 | £16,008.00 | £223,305.71 |
| 4 | 12 | £6,083.70 | £9,924.30 | £0.00 | £16,008.00 | £217,222.01 |
| 5 | 12 | £6,363.19 | £9,644.81 | £0.00 | £16,008.00 | £210,858.82 |
| 6 | 12 | £6,655.49 | £9,352.51 | £0.00 | £16,008.00 | £204,203.33 |
| 7 | 12 | £6,961.26 | £9,046.74 | £0.00 | £16,008.00 | £197,242.07 |
| 8 | 12 | £7,281.05 | £8,726.95 | £0.00 | £16,008.00 | £189,961.02 |
| 9 | 12 | £7,615.57 | £8,392.43 | £0.00 | £16,008.00 | £182,345.45 |
| 10 | 12 | £7,965.40 | £8,042.60 | £0.00 | £16,008.00 | £174,380.05 |
| 11 | 12 | £8,331.32 | £7,676.68 | £0.00 | £16,008.00 | £166,048.73 |
| 12 | 12 | £8,714.08 | £7,293.92 | £0.00 | £16,008.00 | £157,334.65 |
| 13 | 12 | £9,114.42 | £6,893.58 | £0.00 | £16,008.00 | £148,220.23 |
| 14 | 12 | £9,533.09 | £6,474.91 | £0.00 | £16,008.00 | £138,687.14 |
| 15 | 12 | £9,971.06 | £6,036.94 | £0.00 | £16,008.00 | £128,716.08 |
| 16 | 12 | £10,429.13 | £5,578.87 | £0.00 | £16,008.00 | £118,286.95 |
| 17 | 12 | £10,908.24 | £5,099.76 | £0.00 | £16,008.00 | £107,378.71 |
| 18 | 12 | £11,409.37 | £4,598.63 | £0.00 | £16,008.00 | £95,969.34 |
| 19 | 12 | £11,933.50 | £4,074.50 | £0.00 | £16,008.00 | £84,035.84 |
| 20 | 12 | £12,481.73 | £3,526.27 | £0.00 | £16,008.00 | £71,554.11 |
| 21 | 12 | £13,055.15 | £2,952.85 | £0.00 | £16,008.00 | £58,498.96 |
| 22 | 12 | £13,654.90 | £2,353.10 | £0.00 | £16,008.00 | £44,844.06 |
| 23 | 12 | £14,282.19 | £1,725.81 | £0.00 | £16,008.00 | £30,561.87 |
| 24 | 12 | £14,938.33 | £1,069.67 | £0.00 | £16,008.00 | £15,623.54 |
| 25 | 12 | £15,623.54 | £383.42 | £0.00 | £16,006.96 | £0.00 |
What is the repayment on a £240,000 mortgage at 4.5%?
Under the equal-monthly-period model, £240,000 at an illustrative 4.5% over 25 years gives an initial £1,334.00 repayment and £160,198.96 total interest if that rate lasts throughout. Assuming 6% after a five-year initial deal instead leaves £210,858.82 at the change, followed by £1,510.66 monthly over the remaining 20 years. These examples exclude fees, home costs and overpayments. They use monthly interest rounding, not lender-specific daily interest or an actual rate offer.
Reviewed October 25, 2026 by DollarMath. Educational estimates. Sources and calculation scope.
Common questions
Is a five-year fix the same as a five-year repayment term?
No. The deal length describes how long the initial rate lasts. The full repayment term is the period used to repay the mortgage, such as 25 years. Enable the follow-on assumption to enter a shorter initial deal and a second rate. Without it, the initial rate lasts for the entire projection. Neither option predicts future mortgage rates.
What happens at the assumed follow-on rate?
The new rate starts the month after the entered initial deal ends. The model recalculates the regular payment from the outstanding debt over the remaining original repayment term, then continues your monthly overpayment on top. That rate is held constant afterward. If the mortgage is already paid off, no follow-on payment is needed. Future remortgage fees and rate changes are excluded.
How much is £240,000 at 4.5% over 25 years?
The model gives £1,334.00 initially each month before fees, home costs and overpayments, using the annual contract rate divided by 12. Holding that rate gives £160,198.96 total interest over 300 payments. If an assumed 6% starts after five years, the remaining £210,858.82 is repaid at £1,510.66 monthly over the remaining 20 years. The final payment settles rounding residue.
Does this reproduce my lender’s daily interest and overpayment rules?
No. It uses equal monthly periods and pence-rounded monthly interest. Overpayments reduce capital and can shorten the projection while the regular payment is held constant between rate quotes. At the optional rate change, the payment is recalculated over the remaining original term. Lenders can use daily interest and different recalculation rules. Check your contract’s allowances and early-repayment charges; no universal penalty-free allowance is assumed.
Are product fees and purchase taxes included?
Only the amounts entered. A product fee added at the start increases the mortgage balance and earns interest. Cash purchase costs include only your entered fees and applicable SDLT, Scottish LBTT or Welsh LTT quotes, separate from the deposit. No regional tax, rebate, lender approval or settlement adjustment is inferred. Include each fee once. APRC is not calculated.
Can I use it for interest-only, offset or shared-ownership mortgages?
No. It models capital repayment with one optional assumed rate change. Interest-only balances, offset accounts, shared-ownership rent, arrears, payment holidays, daily calendars, tax relief and lender affordability checks need different models. Other home costs are a fixed entered monthly allowance; zero omits them. These costs can continue after mortgage payoff.
Can I save plans or use my results in Excel or Google Sheets?
Yes. Save named plans in this browser without an account, then reopen, compare, rename or duplicate them. JSON backups can restore editable plans after local validation and a review step. Download a spreadsheet for typed inputs, results and detailed schedules where available, then open it in Excel or import it into Google Sheets yourself. Workbooks are snapshots, not live calculator formulas. Plans and files are not encrypted; clearing browser data can remove device plans. Nothing is automatically uploaded or synchronized.
Know the assumptions.
Calculation version gb-monthly-repayment-v1. Sources and independent examples checked October 25, 2026; qualitative source review due November 25, 2026. How calculations are checked.
A repayment term and an initial deal are different
The full repayment term is 1 to 40 whole years. The initial interest rate lasts for that whole projection unless you enable the follow-on assumption. With it enabled, enter a 1 to 10-year initial deal shorter than the repayment term. The new rate applies from the following month and is then held constant. The model recalculates the payment from the remaining balance over the unexpired original term and keeps your monthly overpayment on top. It does not predict an SVR, track Bank Rate, remortgage automatically or add fees at the change.
Monthly mathematics, with visible rounding
Round price, deposit and fees to pence. Starting debt is price minus deposit plus the fee added to the mortgage. For monthly rate i = annual interest rate / 100 / 12 and n monthly payments, the repayment is P × i / (1 − (1 + i)^−n), or P / n at zero interest. Round the payment and each month’s interest to pence; settle rounding residue in the final payment. This is a planning convention. Lenders can calculate daily interest, collect a different first payment and recalculate after overpayments.
A £300,000 property with a £60,000 deposit gives £240,000 borrowed. At an illustrative 4.5% over 25 years, the initial repayment is £1,334.00. Holding that rate gives £160,198.96 total interest over 300 payments. Assuming 6% after five years instead leaves £210,858.82 at the change, then a £1,510.66 repayment over the remaining 20 years, with £202,597.59 total interest. A separate 50-digit Decimal recurrence checks these examples, annual balances, rate changes and overpayments. They are not lender quotes.
Overpayments and fees
Monthly overpayments follow interest; the one-off amount follows the selected regular payment. Extras stop at payoff and are capped at debt owing. Between the initial and follow-on quotes, the regular payment is held constant, so extras can shorten the projection. At the rate change it is recalculated over the remaining original term. Your lender’s overpayment treatment, allowances and early-repayment charges can differ. No universal penalty-free allowance is assumed.
A product fee added at the start increases debt and earns interest. Cash-paid purchase costs stay outside debt. Include each fee once. The modelled loan-to-value ratio includes the financed fee; it is not a lender’s product-band or eligibility decision. Enter the contract interest rate, not a fee-inclusive APRC. Regulatory APRC and later remortgage costs are excluded.
Home costs and regional boundaries
Other home costs are your fixed monthly allowance and do not repay principal. Purchase cash is deposit plus entered cash costs, before deposits already paid or settlement adjustments. SDLT in England and Northern Ireland, LBTT in Scotland and LTT in Wales are not inferred. Enter applicable quoted taxes with the cash purchase costs. Recurring costs can include council tax or Northern Ireland domestic rates, insurance and service charges. Zero omits those costs.
The yearly table separates capital, interest and home costs, including a partial final year. Cash through payoff adds mortgage payments, deposit, cash-paid purchase costs and home allowances over that horizon. The financed fee is already in mortgage payments. Home costs can continue after payoff; their shorter displayed horizon is not lifetime ownership savings.
Supported scenarios
This tool excludes interest-only, offset and shared-ownership models, arrears, payment holidays, daily calendars, tax relief, benefit eligibility, lender affordability checks, contract enforcement and property-value changes. Named GBP mortgage plans, JSON backups and Excel snapshots are separate from Canadian and US mortgages and other GBP tools. Inputs stay in your browser unless you choose to export them.