Fixed Deposit Calculator
Calculate interest earned on a lump-sum fixed deposit
Input
Result
This calculator is for informational purposes only and should not be considered as financial advice. Actual values may vary.
What is Fixed Deposit Calculator?
The Fixed Deposit Calculator helps you determine the maturity amount and interest earned when you place a lump sum of money in a fixed deposit account (also called a time deposit or jeonggi yegeum in Korean). Fixed deposits are one of the safest savings instruments, offering guaranteed returns at a predetermined interest rate for a specified term. This calculator supports both simple and compound interest calculations. With simple interest, you earn interest only on the original deposit amount: Interest = Principal × Rate × Time. With compound interest, earnings are reinvested so you earn interest on your accumulated balance: A = P(1 + r/n)^(nt). The calculator also factors in Korean tax treatment options — general taxation (15.4%), preferential taxation (9.5%), and tax-free — to show you the actual after-tax maturity amount. Comparing simple versus compound interest results side by side reveals how compounding boosts your returns, especially for longer terms. Fixed deposits are protected by the Korea Deposit Insurance Corporation (KDIC) up to 50 million won per person per institution, making them an excellent choice for risk-averse savers. Use this calculator to evaluate different deposit offers, optimize your term selection, and accurately forecast your savings growth.
How to Use
- Enter the deposit amount.
- Enter the annual interest rate (%) and term (months).
- Select the tax type and interest type (simple/compound).
- Review the net maturity amount.
Tips & Best Practices
- Compare simple and compound interest options for the same deposit to understand the real difference in returns — compound interest always yields more at the same nominal rate.
- Consider splitting large deposits across multiple banks to stay within the 50 million won deposit insurance limit per institution.
- Lock in higher rates during periods of rising interest rates, as fixed deposit rates are guaranteed for the full term regardless of future rate changes.
- Check if your bank offers preferential rates for online-only accounts, loyal customers, or bundled financial products.
- Create a deposit ladder by splitting your lump sum into deposits with staggered maturity dates (3, 6, 9, 12 months) to balance liquidity and returns.
Use Cases
Lump Sum Savings
Calculate the maturity amount for an inheritance, bonus, or other windfall placed in a fixed deposit.
Simple vs Compound Comparison
Compare the returns of a simple interest deposit against a compound interest deposit to see which option maximizes your earnings.
Tax Optimization
Evaluate how much more you earn with preferential or tax-free treatment versus general taxation on the same deposit.
Term Selection
Compare 6-month, 12-month, and 24-month deposit terms to find the optimal balance between liquidity needs and interest earned.
FAQ
What is the difference between simple and compound interest?
Simple interest is calculated only on the principal, while compound interest is calculated on both principal and accumulated interest, resulting in higher returns.
What is the difference between fixed deposit and installment savings?
A fixed deposit places a lump sum at once, while installment savings makes monthly deposits. For the same total amount, fixed deposits earn more interest.
What is a fixed deposit (time deposit)?
A fixed deposit is a savings product where a lump sum is deposited at a bank for a set term and earns a guaranteed interest rate at maturity. It typically offers higher rates than installment savings.
How much deposit insurance protection is available?
In Korea, the Depositor Protection Act covers up to 50 million KRW per person per financial institution, including both principal and interest.
Is my financial data stored?
No, all calculations are performed in your browser and no financial data is sent to or stored on any server.
Is compound interest always better than simple interest for deposits?
At the same rate, compound interest is always better. However, simple interest deposits may offer higher rates in practice, so comparing the net maturity amounts is important.
Is a fixed deposit safer than stock market investments?
Yes, fixed deposits are significantly safer. They offer guaranteed returns at a fixed rate and are protected by the Korea Deposit Insurance Corporation up to 50 million won. However, returns are generally lower than long-term stock market averages.
What happens if I withdraw my fixed deposit early?
Early withdrawal typically results in a penalty rate that is significantly lower than the contracted rate, often 50-70% of the original rate. Some banks may charge additional early termination fees. It is generally better to avoid early withdrawal.
Should I choose simple or compound interest?
Compound interest always yields more than simple interest at the same rate and term. However, some simple interest deposits may offer a slightly higher nominal rate. Always compare the actual maturity amounts using this calculator.
How does the deposit term affect the interest rate?
Generally, longer terms offer higher interest rates because you are locking your money for a longer period. However, this is not always the case — sometimes short-term rates are higher during periods of inverted yield curves.
Can I add money to an existing fixed deposit?
No, fixed deposits are lump-sum products. Once opened, you cannot add to the balance. If you have additional funds, you would need to open a new fixed deposit account.
When is interest paid on a fixed deposit?
Most fixed deposits in Korea pay interest at maturity along with the principal. Some products offer monthly interest payments, which can be useful for income generation but may result in slightly lower effective yields if the interest is not reinvested.