Omikuji Tools Life & Calc

Loan Repayment Calculator

Monthly payment and total interest for mortgages, car loans and personal loans, with the full amortization schedule, prepayment comparison, rate-rise scenarios and borrowing capacity.

Features

  • Monthly payment, total repayment and total interest from the amount, rate and term, with annuity and equal-principal side by side
  • Full amortization schedule (by year or every payment) downloadable as CSV, with optional semi-annual bonus payments
  • Compare prepayment that shortens the term with prepayment that lowers the payment (one-off or yearly)
  • Rising-rate scenarios (with Japan's 5-year/125% rule) and borrowing capacity from income and debt-to-income ratio

Use cases

Planning a mortgage

See how much a 0.5% rate difference changes the total cost of a 35-year loan.

Deciding on prepayment

Compare shortening the term with lowering the payment after a lump-sum prepayment.

Preparing for higher rates

Know your monthly payment in advance if a variable rate goes up.

Comparing car and personal loans

Change the rate and term to compare total interest.

Privacy

Amounts are processed in your browser and never sent to a server. Only when you shorten a share URL is that URL (including the input) sent to the shortening service.

FAQ

Which is cheaper, annuity or equal principal?

Equal principal costs less interest in total. Its payments start higher and fall over time, while annuity payments stay the same, which makes budgeting easier.

Shorten the term or lower the payment?

Shortening the term keeps the payment and saves more interest. Lowering the payment keeps the term and reduces what you pay each month.

What is the 5-year / 125% rule?

Common for Japanese variable-rate annuity loans: the payment is reviewed only every five years and can rise by at most 25%. If it no longer covers the interest, unpaid interest accumulates and is settled at the end.

Why does my bank's figure differ slightly?

Banks differ in how they compute interest (monthly or daily) and round. This tool rounds interest and the payment down and settles the remainder in the last payment.

Related tools

Compound Interest Calculator Price Calculator Bill Splitter Date Calculator Age Calculator
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mo
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Repayment method
Semi-annual bonus payments

The bonus part is repaid separately twice a year (June and December) with semi-annual interest, as is common in Japan.

Prepayment
Rate change scenario (variable rate)
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How much can I borrow?

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Lenders often test with a higher rate than the one you get and cap the ratio at 30–35% of gross income. A comfortable level is often said to be 20–25% of take-home pay.