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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₩820,000,000 Loan Interest (4% / 30yr) - Toolkit

For a ₩820,000,000 loan at 4% over 30 years (equal payment), the monthly payment is about ₩3,914,805 and total interest about ₩589,329,800.

2026Equal-payment (amortizing) formula

Loan principal

Annual rate (%)

Loan term (months)

Grace period (months, optional)

Monthly payment (first month)3,914,805

Total payments1,409,329,800

Total interest589,329,800

Interest calculationShow steps

Total interest589,329,800

Total payments − principal

= 1,409,329,800 − 820,000,000

Repayment schedule (first 12 payments)

No.	Payment	Principal	Interest	Balance
1	3,914,805	1,181,472	2,733,333	818,818,528
2	3,914,805	1,185,410	2,729,395	817,633,118
3	3,914,805	1,189,361	2,725,444	816,443,757
4	3,914,805	1,193,326	2,721,479	815,250,431
5	3,914,805	1,197,304	2,717,501	814,053,127
6	3,914,805	1,201,295	2,713,510	812,851,832
7	3,914,805	1,205,299	2,709,506	811,646,533
8	3,914,805	1,209,317	2,705,488	810,437,216
9	3,914,805	1,213,348	2,701,457	809,223,868
10	3,914,805	1,217,392	2,697,413	808,006,476
11	3,914,805	1,221,450	2,693,355	806,785,026
12	3,914,805	1,225,522	2,689,283	805,559,504

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 ₩820,000,000 Loan

Borrowing ₩820,000,000 at 4% for 30 years (equal payment) gives a monthly payment of about ₩3,914,805, total interest of about ₩589,329,800, and total repayment of about ₩1,409,329,800.

Repayment summary

Monthly payment: ₩3,914,805
Total interest: ₩589,329,800
Total repayment: ₩1,409,329,800

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