Loan interest calculator
Calculate monthly payment and total interest from principal, term, annual rate, and repayment type.
When to use this calculator
Estimate monthly payments and total interest for equal-payment, equal-principal, or interest-only loan repayment.
- Comparing repayment structures
- Estimating a monthly debt burden
- Seeing how term and rate affect total interest
Worked examples
Equal payment
KRW 10,000,000 for 36 months at 5% gives a monthly payment of about KRW 299,709.
Equal principal
Payments start higher and decline as the outstanding balance falls.
Interest only
Interest is paid during the term and principal is due at maturity.
Frequently asked questions
Which method has the lowest total interest?
Equal-principal repayment often reduces principal faster, but actual products and fees differ.
Are fees included?
No. Guarantee fees, stamp tax, insurance, and early-repayment fees are excluded.
What about variable rates?
The calculator assumes the entered annual rate remains constant.
How to interpret the result
Use the lender's repayment schedule for a contract decision.
Consider rate changes, grace periods, fees, and early repayments that are not modeled here.