Deposit & savings interest calculator
Estimate principal, gross interest, tax and maturity value for a lump-sum deposit or monthly savings in KRW.
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Good to know
Simple interest by whole months. Installments are paid at the start of each month; the last earns one month of interest. The editable 15.4% tax default illustrates standard Korean interest taxation.
Savings type: deposit Deposit amount (KRW): 10000000 Annual interest rate (%, 0–100): 4 Term (months, 1–600): 12 Interest tax rate (%, 0–100): 15.4
Understand and use your results
A lump-sum deposit and monthly savings earn interest on different amounts for different periods. Compare gross and net interest while accounting for contribution timing.
How to use it
- Choose deposit or installments and enter the lump sum or monthly contribution.
- Enter the annual rate, term and applicable interest tax rate.
- Read principal, gross interest, estimated tax and maturity value separately.
Worked example
100,000 KRW/month · 12 months 12% annual simple interest · 15.4% tax
Principal: 1,200,000 KRW Gross interest: 78,000 KRW Tax: 12,012 KRW Maturity: 1,265,988 KRW
With 100,000 KRW paid at each month’s start, interest periods are 12, 11, …, 1 months. Installment interest = contribution × annual rate ÷ 12 × n(n+1)÷2, with the rate as a decimal. Deposit interest = principal × annual rate × months ÷ 12.
Does the 15.4% default apply to all savings?
No. It illustrates standard Korean taxation of interest; exemptions, preferential accounts and personal circumstances can differ. Edit the rate to match your case. Gross principal plus interest is capped at 1,000 trillion KRW to preserve whole-KRW precision. This uses simple monthly interest and whole-KRW rounding, without exact day counts, early withdrawal, variable rates or per-tax truncation. Check your bank’s terms for actual payments.