住宅ローン計算機 返済シミュレーターアプリ

The biggest anxiety about home loans is not being able to see the big picture of large numbers—"How much do I pay each month?" and "How much will I end up paying in total?" This app lets you enter just the loan amount, interest rate, and repayment period, and instantly displays your monthly payment, total repayment amount, and total interest. It transforms vague worries into clear numbers, so you can calmly plan your finances.

You don't need to open your bank's website repeatedly. Every time you adjust conditions, results update instantly. You can try "What if the interest rate goes up 1%?" or "What if I shorten the period by 5 years?" as many times as you want, right in your hand.

【We answer these worries with numbers】
・I want to know if my monthly payment fits comfortably in my household budget
・I want to compare how much the total payment changes between variable and fixed rates
・I want to see how my burden lightens with a down payment or bonus payments
・I want to know how much my payment increases if interest rates rise
・I want to think ahead to retirement and know at what age I'll finish paying off the loan
・I want to understand how household repayment works with a pair loan between spouses

【Main Features】

・Real-time monthly payment calculation
Enter the loan amount, interest rate, and repayment period, and instantly calculate your monthly payment, total repayment amount, and total interest. As you adjust the numbers, you'll get a better sense of the burden.

・Compatible with 3 interest rate types
Switch and compare between variable rate / fixed-period selection type (initial fixed then variable) / full-term fixed rate. With the fixed-period selection type, you can also check how your payment changes when the fixed period ends and switches to the assumed rate.

・Both equal principal-and-interest and equal principal payment methods
Switch with one tap. With the equal principal method, you can see the difference between the first and final payment amounts.

・More detailed variable rate analysis
Set up step-by-step interest rate changes ("from which payment number does the rate change?") or set half-yearly interest rate increase forecasts and calculate. Additionally, switch the repayment review rules "5-year rule" and "125% rule" on and off to compare and display how much your payment increases when rates rise.

・Bonus payments
Specify the payment month and amount to add on top of your regular monthly payment. You can visualize how lump-sum payments reduce the balance faster and suppress total interest.

・Completion age automatically displayed
Enter your age at the time of borrowing, and it displays your age at completion. If completion occurs at an advanced age, it alerts you and encourages a realistic repayment period.

・Down payment and property price
Automatically calculate the loan amount and self-funded ratio from the property price and down payment. Useful for deciding how much down payment to make.

・Rough estimate of miscellaneous fees
Displays rough estimates of brokerage fees, administrative fees, registration costs, fire insurance, stamp tax, real estate acquisition tax, and more. You can also calculate what happens if you "include it in the loan."

・Pair loan
Calculate combined figures for two people (spouses/dual-income couples). Displays household monthly payment and total payment, plus estimated ownership ratio based on each person's burden and rough estimates of each person's home loan tax deduction. The full picture of a two-person loan appears clearly on one screen.

・Latest reference interest rates
Retrieves and displays representative interest rate levels (variable, 10-year fixed, Flat 35, etc.) from the internet. You can reflect them in your calculation with one tap (uses built-in default values if retrieval fails).

・Visualized with graphs
Displays the transition of remaining debt, annual breakdown of principal and interest, and the ratio of principal to interest in total repayment through intuitive graphs.

・Repayment schedule table
Displays the full repayment schedule in a list. You can check the detailed breakdown of principal, interest, and remaining balance for each month.

・Unit conversion tool
Instantly convert between square meters, tsubo, and tatami. Also calculates unit price per tsubo from property price (within settings).

・Scenario save and compare
Save conditions with a name and compare/restore them in a list. You can carefully compare multiple plans and choose the one you're confident about.

【Works offline too】
All calculations are completed on your device. Communication is only needed when retrieving the latest reference interest rates. Your input and scenarios are saved only on your device and are not sent to external servers. No tracking or ad display occurs.

【About Usage】
Basic home loan calculations are free to use with no usage limits (monthly payment, total repayment, graphs, repayment schedule, scenario saving/comparison, latest reference rates, etc.). Pair loan combined calculation (household repayment amount, ownership ratio, home loan tax deduction estimates) and miscellaneous fee estimates (calculation) are unlocked with a one-time purchase Pro version (300 yen—no additional charges after purchase). You can try it free for 7 days before purchasing. It is not a subscription.

【Important Notes】
This app is a tool for rough estimation of home loan repayment amounts and does not provide advice on finance, investment, tax, or legal matters. All displayed interest rates, miscellaneous fees, home loan tax deductions, and ownership ratios are representative reference values and estimates; actual interest rates, fees, borrowing capacity, deduction amounts, and approval results vary depending on financial institutions and your circumstances. Home loan