A short bundle for property work: what a loan costs month to month, and what the numbers look like over the full term.
Showing the property is the easy part. What decides the deal is the follow-up question: «what does this actually cost me each month?» An agent who can produce that number in front of the client, instead of deferring it to the bank, closes more of the viewings they run.
The order that works is: agree on the price, subtract the cash the buyer has, run the remainder as a loan, and only then talk about how that monthly payment fits the rest of their life.
Note that the Korean statutory tools in this collection — brokerage fee caps and acquisition tax — appear only in the Korean edition of the site, because they encode Korean law rather than a general formula. This page focuses on the two calculations that travel across markets.
When a buyer asks «can I borrow 300,000?», the more useful question back is «what monthly payment can you carry without changing how you live?» Start from that figure and derive the principal, and unaffordable deals filter themselves out before anyone signs.
A rough sanity check most lenders apply is that total housing costs should stay under roughly a third of gross income, with all debt payments together under about 40%. Local rules vary, but the ratio is a useful conversation opener.
Remember that the payment is not the whole cost of ownership. Property tax, insurance, maintenance and, in many buildings, service charges all land on top of it — a payment that fits exactly with nothing left over is a payment that does not fit.
Equal instalment (annuity) keeps the total payment identical every month. Early on, most of it is interest; the principal share grows over time. It is the easiest to budget around and the most common default.
Equal principal repays the same slice of principal each month, so payments start high and fall steadily. It costs less in total interest, and it suits a buyer whose income is high now and expected to drop — someone approaching retirement, for example.
Interest-only until maturity keeps monthly cost low but leaves the entire principal due at the end. It is a bridging structure, not a housing plan: it only makes sense when a specific, dated source of repayment already exists.
Showing all three side by side is more persuasive than recommending one. The total-interest column usually makes the trade-off obvious without any argument from you.
On a variable-rate loan, run the payment again at one and two percentage points higher before the client commits. The longer the term, the more a rate move changes the monthly figure — a 30-year loan is far more exposed than a 15-year one.
Stretching the term to make the payment look comfortable is the most common way buyers overextend. Halving the payment by doubling the term can easily more than double the interest paid over the life of the loan.
If a fixed period is offered, note the date it ends. A client who cannot say what happens at the end of that period has not finished deciding.
A mortgage is usually the largest commitment a household ever makes, and a 30-year term overlaps almost exactly with the years they would otherwise be saving for retirement. Every increase in the monthly payment comes out of that.
Running the retirement calculator alongside the loan turns that trade-off into two numbers instead of a feeling. You are not talking the client out of the purchase — you are showing them the choice.
Buyers who have had this conversation come back. The transaction they regret is the one nobody modelled for them.
The figures here are reference estimates. They do not include the lender's own underwriting rules, fees rolled into the loan, insurance requirements, or any local tax.
Lending limits are set by the bank, not by a formula. Treat any figure here as preparation for that conversation, not a substitute for it.
Property taxes and transfer duties differ by country and often by city. Quote them only from the local authority that collects them.