The 3%, 4% and 5% rates are assumptions for comparison. The table divides annual net interest by 12. Actual monthly receipts depend on the payment schedule.
On mobile, scroll each table horizontally to read all amounts.
| Assumed annual rate | Annual gross interest | Annual net interest | Net monthly equivalent |
|---|---|---|---|
| 3% | 3,000,000 | 2,538,000 | 211,500 |
| 4% | 4,000,000 | 3,384,000 | 282,000 |
| 5% | 5,000,000 | 4,230,000 | 352,500 |
For a KRW 1 million monthly budget, the 4% example still leaves KRW 718,000 to fund from other income or savings. This assumes you keep the principal intact and spend only interest. Spending principal reduces future interest, while inflation reduces what the same interest can buy.
How much actually reaches your account each month?
The monthly equivalent is annual interest divided by 12. The contract determines when you receive money.
- Monthly interest payments: interest arrives on the agreed payment dates. With the same 4% rate and 15.4% withholding assumption, KRW 282,000 is a monthly estimate. Actual amounts depend on the product's day-count and tax rounding rules.
- Payment at maturity: no interest arrives in the intervening months. In this 12-month example, KRW 3,384,000 net interest arrives with the principal at maturity. It cannot fund expenses before that date.
Monthly and maturity payment options may have different rates. Compare both the rate and payment schedule. If you plan to spread maturity interest over the following year, you still need cash for expenses before the first maturity.
Monthly payments and monthly compounding are separate concepts. Compounding adds interest to the balance that earns future interest. Interest withdrawn for expenses does not compound in the deposit. All tables here use simple interest without reinvestment.
How much remains after 15.4% interest withholding?
The standard assumption combines 14% income tax with 1.4% local income tax. Tax applies to interest, not principal. At 4%, KRW 4,000,000 gross interest minus KRW 616,000 withholding leaves KRW 3,384,000. National Tax Service withholding rates · KB tax and deposit guidance
Tax-exempt comprehensive savings and other exceptions depend on eligibility, limits and account terms. A KRW 100 million deposit is not automatically fully exempt. Confirm that the benefit applies to your account before selecting an exempt calculation.
Annual taxable interest and dividends above KRW 20 million generally require review for comprehensive financial income taxation. Exempt and separately taxed income have their own rules. The 15.4% deduction therefore does not determine every person's final tax bill. National Tax Service financial income guidance
What principal produces KRW 1 million a month?
At an assumed 4%, you need approximately KRW 354.61 million to produce the equivalent of KRW 1 million a month after standard withholding. That means depositing roughly KRW 255 million more than the original KRW 100 million. The table below also compares monthly equivalents after withholding.
| Net monthly target (KRW) | Assumed 3% | Assumed 4% | Assumed 5% |
|---|---|---|---|
| 500,000 | 236,406,620 | 177,304,965 | 141,843,972 |
| 1,000,000 | 472,813,239 | 354,609,930 | 283,687,944 |
| 2,000,000 | 945,626,478 | 709,219,859 | 567,375,887 |
A KRW 2 million monthly target implies about KRW 28.37 million gross annual interest. That deposit alone exceeds the usual KRW 20 million comprehensive taxation threshold. This row illustrates withholding only. The principal required after final tax may be higher.
What happens when the rate falls by one percentage point?
If you renew at 3% instead of 4%, the net monthly equivalent on KRW 100 million falls from KRW 282,000 to KRW 211,500. The principal stays the same, but the amount available for expenses falls by KRW 70,500 a month, or 25%. With the same withholding, a one percentage point fall reduces annual net interest by KRW 846,000.
A fixed-rate deposit keeps its contracted rate during its term. The lower market rate usually affects this budget when you renew at maturity. A one percentage point fall is different from a 1% relative decline.
How do assumed rates differ from actual bank offers?
The 3%, 4% and 5% table does not compare named bank products. Actual rates vary with bank, term, sales channel, preferential conditions and payment method. A headline maximum rate may not apply to your entire principal.
For example, the official KB Star term deposit page distinguishes basic, customer-applied and early withdrawal rates. Check the bank's application screen for the rate that applies to your chosen term and payment method.
Use FSS Financial Products at a Glance and the Korea Federation of Banks rate comparison to find candidates. Then check the current bank disclosure for term, gross rate, preferential conditions and payment dates.
Does a KRW 100 million principal leave room for protected interest?
From September 1, 2025, the protection limit is KRW 100 million per depositor per financial institution, including principal and prescribed interest on covered products. Multiple accounts and branches of the same bank are combined. A principal of KRW 100 million already uses the limit, so interest is not fully covered on top. When splitting funds across institutions, include existing covered balances at each institution. Financial Services Commission implementation notice
Prescribed interest is the lower of contracted interest and interest determined by KDIC. Check the product's protection statement. KDIC protection limits · FSC protection FAQ
Early withdrawal may apply a lower rate and remove preferential benefits. For a monthly payment product, check how previously paid interest is settled on early withdrawal. Locking up money needed soon can reduce the interest you ultimately receive.
If you want interest to cover KRW 1 million of monthly expenses, see how much more you need to save at different rates.
Calculate with your own principal and term
How much interest would your own savings earn? Enter your deposit amount and the rate and term of the product you are considering to check interest after tax.
Open the deposit interest calculatorFrequently asked questions
What if I deposit for six months?
KRW 100 million at 4% simple interest with 15.4% withholding produces KRW 2,000,000 gross and KRW 1,692,000 net over six months. Actual products may use different day-count rules.
Does a 4% installment savings account earn the same interest?
No. A lump-sum deposit earns interest on the full principal from the start. Monthly installment contributions earn interest for different lengths of time. These tables describe a lump-sum deposit.
Will closing a one-year deposit after six months earn the six-month interest above?
Not necessarily. Holding a six-month deposit to maturity differs from closing a one-year deposit early. An early withdrawal rate can leave you with less than the KRW 1,692,000 net example above. If you have already received monthly interest, check how the bank settles those payments on closure.
Detailed calculation assumptions
Checked 2026-10-09. Assumptions: KRW 100 million, 12 months, simple interest and 15.4% standard withholding. Gross interest = principal × annual rate × months ÷ 12. The existing engine rounds gross interest and tax to two decimal places with HALF_UP. The monthly equivalent divides annual net interest by 12 and rounds to two decimals. Displayed amounts use whole-KRW HALF_UP rounding. Required principal rounds up to a whole KRW.
Monthly equivalents can differ from the sum of actual monthly payments because of tax settlement. Product-specific day counts, payment dates, tax truncation, additional comprehensive income tax, inflation and renewal rates are excluded. These examples describe a Korean resident individual's KRW deposit. No currency conversion applies.
Required principal = monthly target × 12 ÷ [annual rate × (1 − 0.154)]. Use 0.04 for 4%. To reproduce the annual result in the deposit interest calculator, enter KRW 100,000,000, 12 months, 4%, simple interest and standard tax. The calculator does not provide a payment-date cash schedule.
These are calculation examples, not financial or tax advice. Confirm actual rates, payments and personal tax treatment using the product disclosure. Disclaimer