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Buying a home: what the mortgage will cost, and which deal
Enter the price and your deposit, then choose the kind of deal you are considering. You get the monthly payment at the rate you would realistically be offered for that deposit, the cash you need on completion day including stamp duty, what a bigger or smaller deposit changes, and what you will still owe when the first deal ends. Further down, every kind of deal is compared side by side.
Rate used: the Bank of England's quoted 2-year fixed rate for borrowing about 90% of the price — 5.16%. It is the most competitive headline rate with the fewest conditions, excluding fees, for August 2026 (published around 7 September), 21 days old. Your own rate depends on the product, its fee, your circumstances and the lender; a quote or offer is the definitive figure.
Your monthly cost
What you pay, and what is left
Over 30 years at this rate you would repay £483,123 on a £245,500 loan — £237,623 of it interest. Slide along the chart to see, at any point, what you have paid, how much of it was interest, and what remains.
- Paid so far: £32,208 — £24,985 interest and £7,223 off the loan
- Interest is 78% of what you have paid so far
- Still to pay: £450,914 (93% of the total)
Cash to complete
Everything you need in the bank on completion day.
- Deposit£27,500
- Stamp Duty Land Taxnothing to pay at this price£0
- Total£27,500
Solicitor, survey, broker and moving costs aren't included yet: there is no published market figure for them, so add your own quotes under More options and the total updates.
First-time buyer relief applied.
Stamp Duty Land Tax from the official rates for 2026-09-20 (source). We re-checked those pages on 2026-09-20 and they still show these figures. It covers a standard residential purchase; not mixed-use land, companies, or the exemption for replacing your only main home.
What a bigger or smaller deposit does
Lenders charge less the more you put down. Each row is the market rate for that deposit, so you can see what extra cash buys — against what it asks of you today.
- 5% deposit5.52%
- 10% deposit5.16%you are here · and still here when the deal ends
- 15% deposit5.02%
- 25% deposit4.92%
- 40% deposit4.79%
| Deposit | Cash | Change | Rate | Monthly | vs now |
|---|---|---|---|---|---|
| 5% | £13,650 | −£13,850 | 5.52% | £1,476 | +£134 |
| 10% | £27,300 | −£200 | 5.16% | £1,343 | +£1 |
| 15% | £40,950 | +£13,450 | 5.02% | £1,249 | −£93 |
| 25% | £68,250 | +£40,750 | 4.92% | £1,089 | −£253 |
| 40% | £109,200 | +£81,700 | 4.79% | £858 | −£484 |
Rates are the Bank of England's quoted market figures, not offers; the monthly change is measured against the market rate for your own deposit so the comparison is like-for-like. A bigger deposit also ties up more cash, and the gap between deposit sizes changes over time.
When the deal ends
After 2 years you would owe £238,277 — 87.3% of what the home is worth if it is worth what you paid.
The chart holds the property's value flat, so it understates how far your debt could fall against the home's value if prices rise, and overstates it if they fall. It assumes the same rate and payment throughout. Your lender will value the property when you switch.
Compare every kind of deal side by side
The same loan on each deal the Bank of England publishes a rate for at your deposit. Choose how far ahead to look, what happens when a deal ends, and whether rates move.
What if Bank Rate moves? These scenarios are the largest moves in the Bank's own history over any two years, not predictions. They hit variable deals straight away and every deal once its rate resets.
Side by side, 5 years on
£245,500 borrowed (89.9% of the price) over 30 years, repayment. Tap a deal to see how much of the home is yours over time.
How much of the loan you have repaid
What you pay each month
Steps show a deal ending; slopes show a variable rate moving. After a deal ends the rate becomes the revert-to-rate (6.58%, Bank of England).
Your share of the home: 2-year fixed
- The home is worth £273,000 (held flat); you own £44,542 of it (16%) and owe £228,458
- You have paid £88,152: £71,110 interest and £17,042 off the loan
Why your deposit changes your rate
Lenders price by how much of the property's value you borrow — its loan-to-value, or LTV. A 90% mortgage and a 75% mortgage on the same house are priced differently, and comparing yourself with one headline “average rate” can make a perfectly good deal look expensive. The Bank of England publishes quoted rates by band; the rate index shows every band with the date the figures belong to.
The rate is a marker, not an offer
The Bank's figure is the most competitive rate with the fewest conditions for each band, taken from Moneyfacts data and averaged over the month. It is a headline rate with fees left out, and it lags by a few weeks because the series is monthly. Two things it cannot tell you: what a product's fee does to the total cost (the fee comparison above shows that for your numbers), and which lenders you can reach. A few lenders sell only direct — first direct is reported to be one — so a broker's whole-of-market comparison will not include them.
When the fix ends: product transfer or remortgage
At the end of the initial deal you have two routes, and the costs differ. Both are shown from the point of view of what usually changes; your lender's own terms decide.
| Product transfer (same lender) | Remortgage (new lender) | |
|---|---|---|
| Range of deals | That lender's own products | The whole market |
| Property valuation | Usually not needed | Usually needed; many deals include a free one |
| Legal work | Usually none | Needed; many deals include free or low-cost legals |
| Affordability re-check | Often skipped | Usually a full assessment |
| Your loan-to-value | Sets the band you are priced in | Sets the band you are priced in |
Either way, the loan-to-value chart above is the useful bit: it shows which band your balance will have reached by then. When you have a real mortgage, the timeline tracks the dates — when you can lock a new deal, when a charge steps down — and a watch is from £5.99, once.
Frequently asked questions
How is the monthly payment worked out?
It is the standard repayment-mortgage payment: the loan, the interest rate and the term give one level monthly payment that clears the loan by the end of the term. The rate used is the Bank of England's quoted rate for your loan-to-value band unless you type in a rate you have been quoted. Interest-only mortgages work differently and are not covered here.
Why does my loan-to-value matter for the rate?
Lenders price in loan-to-value bands, because a smaller loan against the same property is less risky for them. The Bank of England publishes quoted rates at 60%, 75%, 85%, 90% and 95% LTV, and the gap between the top and bottom bands can be more than half a percentage point. That is why this calculator uses the band that matches your own deposit instead of one headline rate.
What costs do I need besides the deposit?
Stamp duty (or the equivalent in Scotland and Wales), solicitor or conveyancing fees, a survey or valuation, any broker fee, any product or arrangement fee you pay up front, and moving costs. The calculator adds them into one cash-to-complete figure. The solicitor, survey and moving amounts are placeholders — replace them with real quotes.
Is the rate I see the rate I will get?
No. It is a market marker: the Bank of England's quoted rate for your band is the most competitive headline rate with the fewest conditions, taken from Moneyfacts data and averaged over the month. It excludes fees, so a lower rate with a large fee can cost more than a slightly higher rate with none. Some lenders also sell only direct, so a broker cannot place them. Your offer is the definitive figure.
Is the stamp duty figure right?
It is calculated from the official published rates, checked on the date shown beside the result, for a standard residential purchase. It does not cover mixed-use property, company purchases, leasehold premiums or the exemption for replacing your only main home. Your solicitor confirms the exact amount.
What is the difference between repayment and interest-only?
With a repayment mortgage each payment covers the interest and repays part of the loan, so the balance falls to zero by the end of the term. With interest-only you pay just the interest, so the balance never falls and the whole loan is still owed at the end. Interest-only payments are lower, but you need a separate plan to repay the loan, and lenders set their own conditions for offering it.
How is a fixed rate different from a variable rate?
A fixed rate keeps your payment the same for the length of the deal, whatever happens to interest rates. A variable rate — a tracker that follows Bank Rate, or a discount off the lender's standard rate — can move up or down during the deal. The side-by-side comparison shows what the largest moves in the Bank of England's history would do to each.
What happens when my deal ends?
Unless you switch, most lenders move you to their revert-to-rate (standard variable rate), which is usually higher than a new deal. That step is the payment cliff in the charts. You can compare it with taking a new deal at today's rate for the same product.
Where do the rate scenarios come from?
They are the biggest rise and fall in Bank Rate over any two-year stretch in the Bank of England's own history in the data we load, with the dates shown. They illustrate how far rates have moved before; they are not forecasts.
Does this calculator store my numbers?
No. Everything is calculated in your browser. The only things fetched from a server are the published Bank of England, Land Registry and stamp duty figures. Your numbers are held in this browser tab only, so they carry to the next calculator.
Rates: Bank of England quoted household interest rates (IUMZICQ, IUMBV34, IUMZICR, IUMB482, IUM2WTL for 2-year fixes; IUMBV42, IUM5WTL for 5-year), monthly, headline rates excluding fees. Stamp duty: gov.uk (England and Northern Ireland), Revenue Scotland, gov.wales — checked 20 September 2026. Figures are estimates from the numbers you enter, using standard level-payment amortisation and a flat property value. This is information, not financial advice; for advice on your circumstances, speak to a mortgage adviser regulated by the FCA.