Japan Mortgage Calculator JPY

How Japanese Mortgages Work

A Japanese housing loan (住宅ローン) amortises like any annuity loan: each month's payment covers that month's interest plus a slice of principal, so the balance falls to zero by the final payment. What makes Japan distinctive is the structure around that arithmetic. Most bank mortgages here are variable-rate (変動金利) with a famous safety valve: the interest rate is reviewed roughly twice a year, but your monthly payment is normally reviewed only once every five years, and each review can raise the payment by at most 1.25 times the previous amount. In a rising-rate world, unpaid interest can silently accumulate instead — a trap this calculator deliberately surfaces by showing total interest at your entered rate as a snapshot, not a forecast.

The bonus repayment split (ボーナス返済) is the second Japanese special. Because salaried workers typically receive summer and winter bonuses, lenders let you route part of the loan's repayment through those months: a smaller payment every month, and a larger instalment every June-ish and December-ish payday (modelled here as July and December). That lowers the regular instalment — useful for monthly cash flow — but it does not make the loan cheaper: the bonus portion accrues interest for six months between instalments, exactly as the schedule below shows. If your bonus is uncertain, treat the bonus share as a risk you are choosing to take.

Flat 35, and why rate type changes the maths

Flat 35 is the government-supported full-term fixed-rate mortgage administered through the Housing Finance Support Agency (JHF): one rate, fixed from the first payment to the last. Its published rate table has two loan-to-value tiers — 90% or less, and above 90% — with loans above the threshold facing different conditions and pricing. A constant-rate annuity model matches that product exactly, which is why this page can state its totals with confidence for full-term fixed loans. Fixed-period selection loans (固定期間選択型) hold a rate for an initial 2–10 year period and then usually revert to variable — for those, the totals here describe only the initial period's behaviour, and the variable-rate rules take over after. The rate-type box above states which simplification applies to your selection.

What the calculator leaves out

With the example inputs — a ¥40,000,000 price, 20% down, the illustrative 2.00% rate and 35 years — the loan is ¥32,000,000, the instalment about ¥106,000 a month and total interest roughly ¥12,500,000. The ¥1,500,000-ish of one-off buying costs on such a purchase — acquisition tax, registration, agent commission (capped by law at about 3% plus ¥60,000 plus consumption tax on resales), stamp duty, fire insurance — are handled only through the cash-needed box, never financed by the loan. Group credit life insurance (団信), which many banks effectively require, can also add to the payment. Nothing here models tax deductions: Japan's mortgage tax credit (住宅借入金等特別控除) applies to owner-occupied homes meeting floor-area and other conditions, and its value depends on your income and the year of purchase — a job for your tax adviser, not a calculator. Treat the results as the repayment structure of the loan, nothing more.

Frequently Asked Questions

What rate should I enter?

Enter the annual rate quoted by your bank or, for Flat 35, the rate published for your application week. The 2.00% pre-filled is an illustrative example only — NOT a current Japanese market rate. Finance Atlas never pre-fills a market rate.

Is a variable rate safe because the payment only rises 1.25x?

The 1.25x cap limits how fast the payment can rise at each five-yearly review — it does not cap the interest you owe. When the rate rises faster than the payment, unpaid interest is added to the balance (a structure banks disclose as 未収利息). Lower payments now can mean a higher balance later; read the variable-rate note next to the rate box before relying on it.

Should I use the bonus repayment option?

It lowers the regular monthly instalment, which helps cash flow, but the bonus portion accrues interest for six months between payments, and your job's bonus is less certain than your salary. A common discipline is to keep the bonus share modest, or at zero if your bonus varies a lot. This page shows the interest cost of the split so you can decide with numbers instead of instinct.

Does the calculator include the mortgage tax credit?

No. Japan's housing loan tax credit depends on the property, the purchase year, your income and the outstanding balance — rules that change with tax reform. The totals here are the pure loan arithmetic. Ask a licensed tax adviser (税理士) what the credit is worth in your case.

How much down payment do I need in Japan?

There is no single universal minimum. A 10% down payment (90% LTV) is a common reference point: Flat 35's published pricing distinguishes loans at or below 90% LTV from loans above 90%, which can face different conditions and pricing, and many banks look for around 10% or more. A larger deposit typically improves both approval odds and the offered rate. The down-payment box accepts any percentage, and the loan-to-value line in the results tells you where you stand.

Are these figures in Japanese yen?

Yes — every amount is in Japanese yen (JPY, ¥), rounded to whole yen. Large results also show the 万 (man) notation used in Japanese property listings, where 4,000万円 = ¥40,000,000.

Related Japan Calculators & Guides

• Japan Home Affordability Calculator — what price your income supports
• Japan Car Loan Calculator — the other big secured purchase
• Guide: Fixed vs Variable Mortgage Rates in Japan
• Guide: Mortgage Affordability Basics in Japan
• Guide: Japan Home Buying Affordability