Savings Interest Calculator
Maturity amount and interest for deposits.
Maturity amount (after tax)
10,296,100원
Estimate only. Actual results may vary by the product’s interest calculation method and tax-favored status.
Scenario AProduct 1
Scenario BProduct 2
Scenario A result
Scenario B result
Estimate only. Actual results may vary by institution's interest calculation method and tax treatment.
Savings vs. installment deposits
A time deposit is a lump sum left untouched until maturity, so the full principal earns interest for the entire term. An installment savings account is funded with equal monthly deposits — money deposited early earns interest for longer than money deposited near maturity, so total interest is lower than a time deposit at the same rate.
How it's calculated
With principal P, annual rate r(%), and term n (months): time deposit simple interest = P × (r/100) × (n/12); time deposit compound (monthly) = P × (1+r/1200)ⁿ − P; installment simple interest = P × (r/100) × (1/12) × n(n+1)/2, with total principal = P × n. Interest income tax of 15.4% is withheld from pre-tax interest.
About interest income tax
Ordinary deposit interest is taxed at 15.4% (14% income tax + 1.4% local tax) in Korea. Certain tax-preferred accounts may carry a lower rate or be tax-exempt — check your product's tax treatment.
Interest tax and deposit protection: headline rate versus what you receive
Advertised deposit rates are pre-tax. Tax is withheld when interest is paid, so the amount received is lower.
| Item | Rate |
|---|---|
| Withholding on interest (14% income tax + 1.4% local) | 15.4% |
The bank withholds this when paying interest at maturity, so a headline 4% yields less after tax.
Large financial income is taxed globally
Combined interest and dividends of 20 million KRW or less a year are settled entirely by withholding, with no return required — which covers most savers.
Above that, the excess is aggregated with other income and taxed at progressive rates, so higher earners face an additional liability net of the tax already withheld.
Spreading maturities or splitting accounts is sometimes suggested, but transfers between spouses can raise gift tax questions.
Deposit protection applies per institution
Protection is per depositor per institution, covering principal and interest together. Splitting across banks multiplies the cover; multiple accounts at one bank share a single limit.
Different branches of the same institution are aggregated, though savings banks are separate companies each with their own limit.
Not every product is covered: deposits and instalment savings are, while funds, equity-linked securities and performance-based products are not.
Simple, compound, and interest at maturity
Term deposits usually pay simple interest on the principal alone, whereas compound products add earned interest back to the base.
Instalment savings work differently: the first month's payment earns a full year's interest while the last earns one month's, so the effective yield is roughly half that of a deposit at the same headline rate.
That is why high advertised savings rates disappoint when read as deposit rates. Compare interest received against total contributions instead.
Legal basis
- Withholding on interest — Income Tax Act art. 129
- Global taxation of financial income — art. 14(3)
- Deposit protection — Depositor Protection Act art. 32