Savings & Deposit Interest Calculator

Accurately calculate interest on savings and deposits to help with financial planning. Choose between simple and compound interest methods, and automatically calculate after-tax amounts.

This calculator applies South Korean tax law (as of 2025).

Product Type

Interest Calculation Method

Monthly Payment (KRW)

Period (months)

Annual Interest Rate (%)

Final Amount

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Principal — Interest (Pre-tax) — Interest Income Tax (15.4%) — Interest (After-tax) —

※ Based on 2025 interest income tax rate of 15.4% (income tax 14% + local tax 1.4%)
※ Tax-exempt products or tax-advantaged products require separate calculation.
※ Actual amounts may vary depending on financial institution terms.

GUIDE

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Korean Savings & Deposit Market and Interest Rate Trends

As of 2025, the Korean deposit and savings market features diverse financial products competing even in a low interest rate environment. According to Bank of Korea statistics, the 2024 average fixed deposit rate was around 3.5%, and fixed savings around 3.7%. Major banks (KB, Shinhan, Woori, Hana) offer base rates of 3.0-3.5% annually, while regional and savings banks offer 0.3-1.0%p higher rates. Internet-only banks (KakaoBank, TossBank, KBank) leverage low operating costs to offer 0.5-0.8%p higher rates than major banks. Savings banks offer higher rates (4.5-5.5%) within the deposit protection limit (50 million won), but credit ratings and financial soundness should be verified. Interest income tax is 15.4% (14% income tax + 1.4% local tax). Tax-exempt or tax-advantaged products can reduce taxes.

Difference Between Deposits and Savings and How to Choose

Deposits and savings differ fundamentally in saving method and interest calculation. A deposit (time deposit) stores a lump sum until maturity, receiving principal and interest together at maturity. Savings (regular savings) involves monthly payments, receiving principal and interest at maturity. Interest is calculated differently: deposits earn interest on the full principal, while savings earn interest on each monthly payment differently. For example, saving 12 million won over a year: the deposit earns interest on the full 12 million for 12 months, but savings earns interest on the first payment (1 million) for 12 months, the second for 11 months, etc. So at the same rate, deposits earn more actual interest. At the same 3.5% rate, a 12 million won deposit earns about 420,000 won, savings about 230,000 won. Deposits suit lump sums, savings suit building a monthly habit.

Simple vs Compound Interest and Return Comparison

Interest calculation divides broadly into simple and compound. Simple interest calculates interest only on principal, and most deposits/savings run on simple interest. Compound interest earns interest on interest, growing larger over longer periods. For example, 10 million won at 4% simple interest for 5 years earns 2 million won total interest. Compound interest yields 12,166,530 won—about 16,653 won more. The compounding effect grows with higher rates and longer periods; over 10+ years, compound returns can be 30-50% higher than simple. Saving 1 million won monthly for 20 years at 5% compound yields 41 million won (24M principal + 17M interest), while simple yields 36 million won—a 5 million difference. In practice, equity funds or ETFs are better suited than deposits to enjoy long-term compounding.

Comparing Rates Across Institutions and Choosing the Best Product

Rates differ across institutions, so comparison is essential. As of 2025, major banks' 1-year fixed deposit base rate is 3.0-3.5%, with 0.5-1.0%p added for preferential conditions (salary transfer, card usage, auto-transfer). Shinhan can reach 4.0% (3.2% base + up to 0.8%p preferential). When choosing: first, compare nationwide rates on the FSS comparison site (finlife.fss.or.kr). Second, check whether preferential conditions are achievable. Third, consider early termination penalties—most early termination rates apply only 50-70% of the agreed rate, so keep needed funds separate. Fourth, consider the deposit protection limit (50 million won) and distribute amounts above 50 million across multiple banks for safety.

Interest Income Tax and Tax-Exempt/Tax-Advantaged Products

Interest income tax of 15.4% (14% income tax + 1.4% local tax) is automatically withheld from deposit/savings interest. Depositing 10 million won at 4% for a year earns 400,000 won interest, but only 338,400 won is received after 61,600 won tax. To gain tax exemption, use specific products. First, long-term housing savings allow individuals with annual income under 70 million won who don't own homes, fully exempting interest income tax if held 7+ years at up to 250,000 won/month. Second, the Noran Umbrella mutual aid for small businesses provides income deduction (up to 5 million won) and interest income tax exemption. Third, cooperative deposits (Saemaul Geumgo, Sinhyup, Nonghyup) apply a 1.4% low tax rate up to 30 million won. Fourth, tax-preferred comprehensive savings apply only 9.5% interest income tax up to 100 million won per person. These can save tens to hundreds of thousands of won annually.

Savings Maturity Planning and Lump-Sum Building Strategy

Savings require clear goals and period setting. Period and amount vary by purpose—wedding funds, home purchase, child education, retirement. For example, if you need 30 million won in 3 years, you must pay about 800,000 won/month into a 3.5% savings account. Saving 20-30% of income is recommended. For 3 million won monthly income, allocating 600,000-900,000 won to savings is appropriate. Strategy: first, set up auto-transfer to save right on payday ("save first, spend later"). Second, run multiple savings with staggered maturities for liquidity—two 1-year savings opened 6 months apart provide a lump sum every 6 months. Third, choose long-term (3-year) savings when rates are high and short-term (1-year) when low. Fourth, manage bonuses in separate lump-sum deposits to maximize interest.

Early Termination and Post-Maturity Management

Terminating deposits/savings early applies a lower early-termination rate, causing loss. Most banks' early termination rates are 50-70% of the agreed rate, and termination under 6 months applies only the ordinary deposit rate (0.1-0.5%). For example, terminating a 4% 2-year savings after 1 year applies only about 2.5%, reducing interest by 37.5%. To avoid early termination: first, set an amount and period you can maintain to maturity. Second, keep emergency funds separately for unexpected expenses—recommended emergency funds are 3-6 times monthly income. Third, use savings products with a "partial withdrawal" feature. Post-maturity management matters too—if not auto-terminated at maturity, a low post-maturity rate (1-2%) applies. Apply for a 1-month-before alert and terminate at maturity to re-enroll in a higher-rate product.

Deposit Protection System and Choosing Safe Institutions

The deposit protection system protects depositors' principal and interest when an institution fails. As of 2025, up to 50 million won (principal + interest combined) is protected per person per institution. Most institutions—banks, savings banks, credit unions, Saemaul Geumgo, securities firms, insurers—are covered. Amounts above 50 million are not protected, so distribute large funds across institutions. For example, with 200 million won, depositing 50 million each across 4 banks protects the full amount. Criteria for safe institutions: first, a higher BIS capital ratio indicates better soundness—8%+ is normal, 10%+ is sound. Second, choose institutions with high credit ratings. Third, large major banks are relatively safe, while savings banks offer higher rates but with higher risk.

Using the Savings Calculator and Optimizing Financial Planning

The savings/deposit interest calculator handles complex interest calculations automatically, helping predict the exact maturity amount. Enter payment amount, period, rate, and simple/compound method to compute principal, pre-tax interest, interest income tax (15.4%), after-tax interest, and final amount. For example, paying 1 million won/month for 24 months into a 3.5% simple savings yields 24 million won principal, about 730,000 won pre-tax interest, about 110,000 won tax, about 620,000 won after-tax interest, and about 24.62 million won final amount. Strategy: first, compare returns across products. Second, set a goal and reverse-calculate the required monthly payment. Third, compare simple vs compound. Fourth, grasp pre-tax and after-tax interest accurately to plan on a take-home basis. Ignoring the 15.4% tax may disrupt planning. Review various scenarios via simulation to build the optimal savings/investment strategy for your risk tolerance and goals.

Special Promotional Deposits and Event Products Strategy

Financial institutions regularly launch special promotional deposits or event products that offer 0.5-1.5%p higher rates than the market average. These promotions run for a limited time to attract new customers, raise funds, or for marketing purposes. According to Financial Supervisory Service (FSS) statistics, the average rate on special promotional deposits in 2024 was 4.5%, 1.3%p higher than regular deposits (3.2%). For example, KB Kookmin Bank ran quarterly promotions such as the "KB Star Time Deposit," offering 4.3% annually, while Shinhan Bank offered 4.5% through its "SOL Time Deposit Special." Internet-only banks have also been aggressive with promotions - KakaoBank's "Parking Account" offered up to 5.0%, and TossBank's "Interest-First Time Deposit" offered up to 5.2%. According to a survey by the Korea Financial Consumer Federation, using special promotional deposits can earn about 500,000-1,000,000 won more in annual interest compared to regular deposits. Strategies for using promotions: first, regularly check bank websites and financial communities for promotion information. Second, since promotional deposits have limited quantities and close early, you need to sign up quickly - in 2024, popular promotions often sold out the same morning they launched. Third, check promotion conditions in advance (new customer requirements, minimum deposit amount, preferential rate conditions, etc.) - some promotions only apply the top rate to new customers or those meeting specific conditions. Fourth, compare promotions across multiple banks to choose the highest rate; the FSS financial product comparison site allows you to compare promotional products. Fifth, when a deposit matures, re-enroll in another promotional product to continuously benefit from higher rates. The Korea Financial Education Institute analyzed that actively using promotional deposits over 30 years could yield about 50 million won in additional interest income.