Equal payment vs equal principal?

Equal payment keeps the monthly amount constant; equal principal has a higher early payment but lower total interest.

What rate and term does this assume?

This page assumes 4.0% over 30 years (360 months), equal payment. Change the rate and term in the calculator.

Does early repayment reduce interest?

Yes — repaying principal early reduces the remaining interest, though early-repayment fees may apply.

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₩510,000,000 Loan Interest (4% / 30yr) - Toolkit

For a ₩510,000,000 loan at 4% over 30 years (equal payment), the monthly payment is about ₩2,434,818 and total interest about ₩366,534,480.

2026Equal-payment (amortizing) formula

Loan principal

Annual rate (%)

Loan term (months)

Grace period (months, optional)

Monthly payment (first month)2,434,818

Total payments876,534,480

Total interest366,534,480

Interest calculationShow steps

Total interest366,534,480

Total payments − principal

= 876,534,480 − 510,000,000

Repayment schedule (first 12 payments)

No.	Payment	Principal	Interest	Balance
1	2,434,818	734,818	1,700,000	509,265,182
2	2,434,818	737,267	1,697,551	508,527,915
3	2,434,818	739,725	1,695,093	507,788,190
4	2,434,818	742,191	1,692,627	507,045,999
5	2,434,818	744,665	1,690,153	506,301,334
6	2,434,818	747,147	1,687,671	505,554,187
7	2,434,818	749,637	1,685,181	504,804,550
8	2,434,818	752,136	1,682,682	504,052,414
9	2,434,818	754,643	1,680,175	503,297,771
10	2,434,818	757,159	1,677,659	502,540,612
11	2,434,818	759,683	1,675,135	501,780,929
12	2,434,818	762,215	1,672,603	501,018,714

Showing only the first 12 payments of the full term.

How it's calculated & notes

·With equal-payment repayment the monthly amount stays constant; with equal-principal repayment the principal portion is constant, so interest gradually decreases.
·During the grace period you pay interest only and the principal stays unchanged; after it ends, the principal is repaid over the remaining term. A longer grace period increases total interest.
·Actual loans may differ in total interest depending on prepayment fees, variable rates, and day-count conventions.
·This calculator provides an estimate assuming a fixed rate and equal monthly repayment.

Repayment Analysis for a ₩510,000,000 Loan

Borrowing ₩510,000,000 at 4% for 30 years (equal payment) gives a monthly payment of about ₩2,434,818, total interest of about ₩366,534,480, and total repayment of about ₩876,534,480.

Repayment summary

Monthly payment: ₩2,434,818
Total interest: ₩366,534,480
Total repayment: ₩876,534,480

What is the loan interest calculator?

The loan interest calculator computes the monthly payment and total interest from the principal, annual rate, and term. Equal payment keeps the monthly amount constant; equal principal repays a fixed principal each month, with a higher early burden but less total interest. This page assumes {rate}% over {years} years.

Repayment methods

Equal payment: same monthly amount
Equal principal: same principal, declining interest
Rate and term greatly affect total interest

View the full loan interest table →

Frequently Asked Questions

Equal payment vs equal principal?: Equal payment keeps the monthly amount constant; equal principal has a higher early payment but lower total interest.
What rate and term does this assume?: This page assumes 4.0% over 30 years (360 months), equal payment. Change the rate and term in the calculator.
Does early repayment reduce interest?: Yes — repaying principal early reduces the remaining interest, though early-repayment fees may apply.

Last updated: July 2026 · Sources: 한국은행