Loan & Revolving Payment Calculator
Enter the amount, annual rate and either the number of payments (amortizing or equal-principal loans) or a fixed monthly payment (revolving credit), and this tool estimates the monthly payment, total interest, time to pay off and a month-by-month schedule. For comparing mortgage prepayments, try the Mortgage Prepayment Comparison Calculator.
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Loan details
How to use
- Choose a repayment method: amortizing, equal principal or revolving.
- Enter the amount and the annual interest rate (%).
- Enter the term for loans, or the fixed monthly payment for revolving credit.
- See the monthly payment, total interest and repayment schedule.
Notes
- This is a simplified estimate: a constant rate, payments on the same day each month, and monthly interest of balance × annual rate ÷ 12. Real lenders use daily accrual and due dates, so amounts may differ slightly.
- Revolving credit assumes the fixed-payment method. Other card-issuer schemes, such as fixed principal or balance-sliding payments, are not modeled.
- With the same amount and rate, a low revolving payment stretches payoff out and inflates total interest. Try several payment amounts to compare.
- Guarantee fees, handling fees, annual fees and late charges are not included. Check your contract or statement for real terms.
- Results are for reference only and are not a guarantee of any loan or payment.
Glossary
Amortizing loan (equal payment)
A loan where the total monthly payment (principal + interest) is constant. Early payments are mostly interest, shifting toward principal over time. Easy to budget, but total interest is higher than with equal principal.
Equal-principal repayment
A loan where the principal repaid each month is constant and interest falls with the balance, so payments shrink over time. The early burden is heavier, but total interest is lower than amortizing.
Revolving credit
A scheme where the monthly payment stays fixed regardless of the balance. Monthly burden is light, but fees keep accruing on the remaining balance, so payoff takes long and total fees grow.
Effective annual rate
The yearly cost of borrowing including interest and fees. Card loans and revolving credit in Japan commonly run around 15%.
FAQ
Which is cheaper: amortizing or equal principal?
For the same amount, rate and term, equal principal costs less total interest. Its early payments are larger, though, so choose by balancing monthly burden against the total.
What happens if I set a low revolving payment?
The monthly burden is lighter, but fees keep accruing on the balance, so payoff takes far longer and total fees climb. Try different payments to compare interest and duration.
Why does it say the balance cannot be paid off?
If the monthly payment is not larger than the monthly fee on the balance, the principal never falls. Raise the payment above the monthly fee.
Can this differ from my lender's actual figures?
Yes. It uses a simple monthly rate of annual rate ÷ 12 and ignores daily accrual, due dates, rounding rules and issuer-specific revolving schemes. Treat it as an estimate.
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