Work out the monthly payment, total interest and total cost of a property loan. Useful whether you're financing at home to release cash, or weighing a developer payment plan.
Illustrative repayment calculation only, assuming a fixed rate over the full term. Actual costs depend on the lender, rate changes, fees and currency. Not a mortgage offer or financial advice.
In practice, local Thai mortgages are difficult for most foreign buyers to obtain. A limited number of lenders extend financing to particular nationalities, or to applicants with Thai residency, a Thai work permit or verifiable Thai-sourced income. Where such lending exists it typically comes with a shorter maximum term, a lower loan-to-value ceiling and a higher rate than the borrower would meet at home. Some developers run their own staged payment plans on off-plan units, which function as interest-free instalments across a construction period rather than as a mortgage. Beyond those two routes, the large majority of overseas buyers complete in cash.
That reality changes what this page is for. Most people arriving at a mortgage calculator for an overseas purchase are not costing a loan in the destination country at all — they are costing a loan at home that will release the cash to buy abroad outright. Remortgaging a UK property, drawing on an offset facility, or borrowing against another asset. The arithmetic below applies identically to any of those, because the mathematics of an amortising loan does not care what the money is spent on. What changes is the risk you are carrying, and that is discussed further down.
A repayment mortgage is a single equation solved for one unknown. You have a starting balance, a rate applied monthly, and a fixed number of months. The calculator finds the constant payment that reduces the balance to exactly zero on the final month — no more, no less. That payment never changes, but its composition changes every single month.
Early on, most of what you pay is interest on a large outstanding balance, and only a sliver reduces the debt. As the balance falls, the interest portion shrinks and the capital portion grows, and the process accelerates towards the end. This is why overpaying in year two is worth dramatically more than overpaying in year twenty — you are removing principal that would otherwise have accrued interest for another two decades. It is also why the total interest figure looks so much larger than people expect relative to the rate.
Take the calculator's defaults: £200,000 borrowed at 5.5% over 25 years, on a repayment basis with the rate held flat for the whole term.
Monthly payment: £1,228. Over 300 months that is £368,452 repaid in total, of which £168,452 is interest — 84% of the sum borrowed, paid on top of it.
Now move the rate to 7.5% and change nothing else. The monthly payment rises to £1,478 — £250 more, which sounds survivable — but the total interest rises to £243,395. Two percentage points on the rate cost £74,943 across the term. Rate sensitivity is brutal over long horizons and almost invisible month to month, which is exactly what makes it dangerous.
Now go back to 5.5% and shorten the term to 15 years. The monthly payment climbs to £1,634 — £406 more than the 25-year version — but the total interest collapses from £168,452 to £94,150. You save £74,302 by paying it off faster. Term is the lever most borrowers never touch, and it is frequently the most powerful one available.
Figures are illustrative, rounded, and assume a fixed rate held for the entire term with no fees, no overpayments and no product switches. Real lending does not work that way. This is not a mortgage offer, not advice, and not a prediction of any rate you will be given.
| Scenario (£200,000 borrowed) | Monthly | Total repaid | Total interest |
|---|---|---|---|
| 5.5% over 30 years | £1,136 | £408,808 | £208,808 |
| 5.5% over 25 years (default) | £1,228 | £368,452 | £168,452 |
| 5.5% over 15 years | £1,634 | £294,150 | £94,150 |
| 7.5% over 25 years | £1,478 | £443,395 | £243,395 |
Read that table across rather than down. Stretching from 25 years to 30 saves £92 a month and costs £40,356. Compressing to 15 costs £406 a month and saves £74,302. Every one of those trades is available to you at the application stage and most of them are difficult to change afterwards.
The sum actually advanced, not the property price. If you are releasing equity at home to buy abroad in cash, this is the additional borrowing — not the value of either property. Arrangement, valuation and legal fees are sometimes added to the loan rather than paid up front; if yours are, include them here, because you will be paying interest on them for the full term.
Enter the rate you have actually been quoted. Where you are on a fixed period followed by a reversion rate, the honest approach is to run the calculation twice — once at the fixed rate to see the near-term cost, once at the reversion rate to see what happens if you cannot refinance when it ends. Modelling only the attractive half of a product tells you very little.
The full repayment period. Lenders commonly cap the term by reference to your age at its end, which for buyers in their fifties and sixties frequently constrains this field more than affordability does. If the term you want is not available, the monthly figure changes materially — which is a reason to establish the cap before building a budget around it.
The output is a clean repayment schedule and nothing more. It excludes arrangement and product fees, valuation and legal costs, early repayment charges if you exit a fixed period, and any insurance a lender requires as a condition. It assumes a constant rate, which outside a full-term fix is an assumption rather than a fact.
Two risks matter more here than they would on a domestic purchase. The first is currency mismatch: if you borrow in sterling to buy an asset priced in baht, you have taken a currency position whether or not you meant to. The debt does not move; the value of the thing you bought with it, expressed in the currency you repay in, moves constantly. Rental income earned in baht servicing a sterling loan compounds the same exposure. The second is security: releasing equity from your home to fund an overseas purchase secures a foreign, illiquid, harder-to-value asset against the roof over your head. That may still be the right decision, but it should be a decision made deliberately rather than one discovered later.
On the UK tax side, the treatment of interest on borrowing used for a let property is a genuinely technical area and the rules have changed significantly in recent years. It is mechanics rather than a single rate, and the current position is on GOV.UK. Because this shifts at Budgets, read it there and take advice from an accountant familiar with overseas property rather than working from any figure printed on a website.
Not directly — a UK lender will not take security over Thai property. What people do instead is borrow against a UK asset they already own, most often by remortgaging or taking further advances on their home, and send the released cash abroad to complete in full. That is a UK loan secured on UK property, and it is assessed on your UK circumstances. It works, but it means your UK home is carrying the risk of an overseas purchase.
During construction it usually is, because staged plans are typically interest-free — you are paying the same total price on a schedule. The question is what happens at handover, when any remaining balance falls due as a lump sum. If you will need financing at that point, arrange it before you commit rather than after, because your options at completion are far narrower than your options today.
That is a personal financial planning question rather than a property one, and it turns on your tax position, what else the capital could do, your appetite for leverage and your view on rates. Leverage magnifies outcomes in both directions: it improves the return on your own capital if the asset performs and deepens the loss if it does not. We are an introducer and not a financial adviser — this needs a conversation with someone regulated to have it.
No, it models capital repayment throughout, so the balance reaches zero at the end of the term. An interest-only arrangement has a much lower monthly cost and leaves the entire principal outstanding on the final day, to be met by sale, refinancing or other capital. If that is your structure, the monthly figure here will overstate your outgoing considerably and understate what you owe at the end by the whole loan amount.
Want to know which developments offer payment plans?
See if you qualify →A calculator only answers the question you ask it. See what a Phuket property costs to buy, own, let and sell.