Fixed Deposit Calculator

Calculate interest earned on a lump-sum fixed deposit

Input

Simple-interest estimate; product rounding may differ.

Result

Net Maturity Amount
10,296,100
Interest Earned (pre-tax)
350,000
Interest Income Tax (14%)
49,000
Local Income Tax
4,900
Net Interest
296,100

What is Fixed Deposit Calculator?

This calculator estimates a lump-sum deposit using simple interest and exact integer tax withholding. General treatment separates 14% interest income tax and local income tax. Tax-free treatment requires independent eligibility confirmation. Deposit protection guidance uses a KRW 100 million threshold for protected principal and prescribed interest per depositor at the same institution, but product eligibility must be confirmed separately.

How to Use

  1. Enter the lump-sum principal as a positive whole-won amount.
  2. Enter an annual rate and a term from 1 to 120 months.
  3. Choose tax-free only after confirming product eligibility.
  4. Review the simple-interest estimate, separate taxes, and protection notice.

Tips & Best Practices

  • This calculator uses simple interest and floors the combined integer formula once.
  • Enter a whole basis-point rate represented by the percentage input and a term from 1 to 120 months.
  • Choose tax-free only after the provider confirms product and personal eligibility.
  • General treatment separates 14% income tax and local tax equal to 10% of that tax.
  • The 2025-09-01 KRW 100 million guidance is not a legal decision; confirm the product separately.

Use Cases

Lump Sum Savings

Calculate the maturity amount for an inheritance, bonus, or other windfall placed in a fixed deposit.

Offer Comparison

Compare provider quotations using the same simple-interest assumptions.

Tax Comparison

Compare general taxation with an eligibility-confirmed tax-free estimate.

Term Selection

Compare 6-month, 12-month, and 24-month deposit terms to find the optimal balance between liquidity needs and interest earned.

FAQ

Does this calculator use simple interest?

Yes. It calculates principal × basis points × months ÷ 120,000 and floors the integer formula once.

How is general interest tax calculated?

Interest income tax is 14%; local income tax is 10% of that tax, usually 15.4% in total.

Does the calculator determine tax-free eligibility?

No. Tax-free is a user-selected estimate after eligibility is confirmed with the provider.

What does the KRW 100 million notice mean?

From 2025-09-01, it covers protected principal plus prescribed interest per depositor at the same institution. It is not a legal determination.

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