Home Loan Calculator
Enter the loan amount, interest rate, and loan term to calculate the monthly payment, total repayment, and total interest. Supports the equal principal-and-interest repayment method.
| Loan Amount |
JPY
|
|---|---|
| Interest Rate (Annual) |
%
|
| Loan Term |
years
|
| Year | Annual Payment | Principal | Interest | Remaining Balance |
|---|---|---|---|---|
| {{ row.year }} | {{ fmt(row.payment) }} | {{ fmt(row.principal) }} | {{ fmt(row.interest) }} | {{ fmt(row.balance) }} |
What a mortgage calculation is
This mortgage calculator estimates your monthly repayment, total repayment and total interest from just three inputs: the amount borrowed, the annual interest rate and the term. Before buying a property you can see in concrete figures how much you would be repaying each month and how far the total outlay shifts with the rate, which makes it a useful first step in planning your finances.
The method used here is equal total payments, in which the monthly repayment stays constant. It is the method most often chosen for mortgages in Japan, though another exists — equal principal payments, where the first repayment is large and gradually falls. If you want to compare the two side by side, use the dedicated repayment method comparison tool.
How to use the mortgage calculator
- Enter the amount borrowed Put in what you will actually borrow: the price of the property you plan to buy, less the deposit.
- Enter the annual interest rate Put in the annual rate quoted by the lender you are considering. Variable and fixed rates differ, so trying both makes comparison easier.
- Enter the term Put in the number of years over which you plan to clear the loan. In Japan a maximum of 35 years is common.
- Check the monthly and total repayment As you type, the monthly repayment, total repayment, total interest and the chart all update in real time.
- Look at the repayment schedule Open the repayment schedule and you get a year-by-year list of how principal, interest and the outstanding balance move.
Tips for getting more out of it
- This calculator uses the equal principal-and-interest method, where the monthly payment remains constant throughout the loan term.
- Be sure to check whether your loan uses a fixed rate or a variable rate. Variable rates may cause your payment to change over time.
- Extending the loan term lowers your monthly payment, but increases the total interest paid significantly.
- In Japan, a mortgage tax deduction (住宅ローン控除) may allow you to reduce your income tax based on the outstanding loan balance — check eligibility conditions.
- A common guideline is to keep your repayment ratio (annual repayment ÷ annual income) within 25–35%.
When the mortgage calculator helps
Financial planning before buying a property
It serves at the stage of narrowing down a budget you can live with, by estimating the monthly repayment across several combinations of property price and deposit.
Checking your repayment ratio
You can see what share of your annual income the yearly repayment takes, and know in advance whether it sits inside a lender's assessment criteria, generally around 25 to 35 percent.
A way into considering refinancing
Enter your current terms to see the total repayment, and if you need a fuller refinancing simulation, moving on to the mortgage refinancing simulator gets you as far as the concrete saving.
Looking into the difference between repayment methods
This calculator covers equal total payments only. To compare the difference in total interest against equal principal payments, the mortgage repayment method comparison tool is handy.
Working backwards to a borrowing you can manage
You can also decide the ceiling on what you can pay each month first, then vary the term and rate to search out a realistic figure for how much to borrow.
Mortgage terms explained
- Equal total payments
- The repayment method in which the monthly payment, principal plus interest, stays constant until the loan is cleared. It makes household budgeting easier and is the most widely used method for mortgages in Japan.
- Equal principal payments
- The repayment method in which the principal portion each month is constant and the interest falls gradually as the balance drops. The first payment is larger, but on identical terms the total interest comes out lower than with equal total payments.
- Variable rate
- A rate reviewed at fixed intervals in line with market movements. The initial rate is often set lower, but future repayments carry the risk of moving.
- Fixed rate
- A method where the rate set at the contract stays unchanged until the loan is cleared, or for a set period. Repayments are settled, which makes planning easier, though the rate tends to be set higher than a variable one.
- Repayment ratio
- The share of annual income taken by the yearly repayment. Lenders generally take 25 to 35 percent as the guide in their assessment, and exceeding it may limit how much you can borrow.
- Early repayment
- Paying off a lump sum ahead of schedule on top of the monthly repayment. There are two kinds: shortening the term, and reducing the monthly payment.
- Flat 35
- The product name for a fixed-rate mortgage of up to 35 years, provided by the Japan Housing Finance Agency together with private lenders. Its appeal is the reassurance of a repayment that never changes until the loan is cleared.
- Mortgage tax deduction
- A scheme under which a set proportion of the loan balance at year end is deducted from income tax and residence tax for a set period. It has the effect of lowering the real cost of borrowing.
Frequently Asked Questions
Side Note — The Mystery of the "35-Year" Home Loan
In Japan, the most common home loan term is 35 years. This originated from post-war housing finance policies, where long repayment periods were introduced to make home ownership accessible to more people.
For example, borrowing 30 million JPY at 1.5% over 35 years results in a monthly payment of approximately 91,900 JPY, with roughly 8.58 million JPY in total interest — about 28.6% on top of the principal.
If your income drops or interest rates rise mid-loan, your financial situation can become strained. Keeping a buffer in your monthly budget is always a wise strategy.