Compound Interest Calculator
Enter monthly savings and interest rate to see the post-tax maturity amount, and compare simple vs. compound interest growth via charts.
Enter Savings Conditions
Initial Investment/Principal (KRW)
Monthly Additional Deposit (KRW)
Annual Interest Rate (%)
Savings Period (Years)
Interest Calculation Method
Select Tax Rate
Maturity Receipt Summary
Final Actual Maturity Amount (KRW)90,671,790
Total Principal Paid (KRW)70,000,000
Total Interest Before Tax (KRW)24,434,739
Tax Deduction (15.4%) (KRW)-3,762,950
Net Interest After Tax (KRW)20,671,790
Asset Growth Simulation
Accumulated Principal
Actual Amount (Principal + After-tax Interest)
Detailed Annual Savings Status
Year
Accumulated Principal (KRW)
Accumulated Interest Before Tax (KRW)
Tax Deduction (KRW)
Estimated Amount After Tax (KRW)
1 Year
16,000,000
676,628
-104,201
16,572,427
2 Year
22,000,000
1,694,844
-261,006
23,433,838
3 Year
28,000,000
3,072,126
-473,107
30,599,019
4 Year
34,000,000
4,826,844
-743,334
38,083,510
5 Year
40,000,000
6,978,308
-1,074,659
45,903,648
6 Year
46,000,000
9,546,816
-1,470,210
54,076,606
7 Year
52,000,000
12,553,705
-1,933,271
62,620,434
8 Year
58,000,000
16,021,404
-2,467,296
71,554,107
9 Year
64,000,000
19,973,488
-3,075,917
80,897,571
10 Year
70,000,000
24,434,739
-3,762,950
90,671,790
Simple Interest, Compound Interest, and Tax Common Sense Guide
The Compound Interest Calculator is an asset management simulator that receives the savings principal, monthly deposit amount, and interest rate to simulate in real-time the principle of asset growth where interest earns interest over time, and analyzes the actual maturity receipt amount based on tax benefits.
Key Features
- Various Interest Application Methods: Accurately calculates not only simple interest but also annual compound interest frequently used in commercial financial products, and monthly compound interest where interest compounds every month.
- Multi-Option Tax Rate Reflection: Perfectly simulates not only general deposit and savings interest income tax (15.4%) but also preferential tax rates (9.5%) applied to cooperative deposits, and tax-free (0%) benefits.
- Cumulative Asset Visualization Chart: Clearly shows through a dynamic area graph how the paid principal curve and the after-tax accumulated interest curve diverge as years pass.
How to Use
- What is the difference between simple interest and compound interest?: Simple Interest only accrues interest on the principal you initially deposited. In contrast, Compound Interest adds the generated interest back to the principal over time, rolling in a structure where 'interest generates interest'. The longer the accumulation period, the more the maturity receipt gap between compound and simple interest widens like a snowball.
- What are general taxation, preferential taxation, and tax exemption?: These are the types of taxes you pay to the country when receiving maturity interest from bank deposits and savings. General taxation deducts **15.4%** of the interest, and upon meeting certain conditions (such as agricultural cooperative members), you can receive a preferential tax rate of **9.5%**. Tax exemption is a product with a **0%** interest income tax, meaning you receive the interest fully intact upon maturity.
- Difference in receipt amounts between savings interest rates and deposit interest rates: People often expect to receive 5% of the entire principal as interest at maturity if they deposit money monthly into a savings product with a 5% annual rate. However, since the interest on savings is calculated per diem only for the remaining period from the monthly payment date to the maturity date, the actual interest becomes about 2.5~2.7% of the total principal. Therefore, when rolling a lump sum, the deposit method of putting it all in at once yields much more interest than savings.