아래는 각 계산기의 목적과 가정, 흔한 오류를 한 문단으로 정리한 가이드입니다. 결과 해석에 영향을 주는 전제를 먼저 확인하세요.
This calculator shows what time, rate, and regular contributions actually do to money — which is harder to grasp intuitively than it looks. Enter an initial balance, an annual interest rate, a compounding frequency, and optionally a regular monthly contribution to see your projected future balance and total interest earned. The results are most useful for retirement planning (estimating how much a pension or savings account might grow), for savings goal tracking (how long to reach a target amount), and for comparing the impact of starting early versus delaying contributions. The single clearest insight this calculator provides: the difference between starting at 25 vs. 35 with the same monthly contribution is often 2× to 3× the final balance, entirely due to compounding time. All results assume a fixed rate throughout the period — investment returns in practice are variable and unpredictable.
The Currency Converter Reference helps you understand approximate currency conversions for major world currencies including USD, EUR, GBP, JPY, KRW, CNY, CAD, AUD, CHF, and HKD. Enter an amount and select currencies to get a reference conversion. Important: rates used here are periodically updated reference values — they are not live market rates. For any actual currency exchange transaction, always use the current rate from your bank, broker, or a real-time forex service. This tool is most useful for travel planning, rough cost comparisons, and educational purposes.
The Discount Calculator instantly shows you the sale price and total savings when a percentage or fixed discount is applied to any original price. Whether you're shopping for clothes, comparing Black Friday deals, or checking if a "50% off" sale is really worth it, this tool does the math in one step. Enter the original price and the discount, and you get the final price and the exact dollar amount saved. You can also work backwards — enter the sale price and original price to find the hidden discount percentage.
Use this calculator when you need to understand the true cost of borrowing — not just the monthly payment. Enter the loan amount, annual interest rate, and repayment term to see your monthly payment, total interest paid, and total repayment amount. This is most useful when comparing loan offers with different terms: deciding whether a 3-year or 5-year term is better on the same principal, or checking whether a loan is affordable before accepting an offer. The calculation uses standard amortization, where each monthly payment covers accrued interest first and then reduces the principal. Early in the loan most of each payment is interest; this balance shifts gradually over time. An amortization schedule shows the full breakdown month by month. This calculator uses a fixed interest rate and does not include origination fees, insurance, or prepayment penalties — use the APR figure from your lender for the most accurate comparison between competing offers.
This calculator helps you estimate what you'll actually pay before sitting down with a lender. Enter the home price, down payment, loan term, and interest rate to see your monthly principal and interest payment, total interest over the life of the loan, and full repayment amount. Use it to compare the real financial difference between a 15-year and 30-year mortgage, to see how a larger down payment changes your monthly obligation, or to check whether a specific home price is affordable at current market rates. Important: this calculator covers principal and interest only. Your actual monthly housing cost will also include property taxes, homeowner's insurance, and — if your down payment is below 20% — private mortgage insurance (PMI). For a realistic budget, add those local figures to the result shown here.
The Sales Tax Calculator tells you how much a purchase will cost once tax is added, and how much of a price-inclusive total is tax. Choose a US state to auto-fill the statewide base rate, or enter any custom percentage for local, international, or blended rates. The result shows the tax amount and the total price including tax. This is most useful when budgeting a purchase where the displayed price is pre-tax, when estimating the true cost of a large purchase across different states or countries, or when working backwards from a total to find the pre-tax amount. Note: the rates shown for US states are base statewide rates. Most states allow counties and cities to add additional local sales tax on top — the combined rate in high-tax localities can be 2–4% higher than the state base rate.
The Tip Calculator removes the guesswork from tipping at restaurants, cafes, hotels, and for service providers. Enter the bill amount, select a tip percentage, and specify how many people are splitting the check — you'll instantly see the tip amount, total bill, and each person's share. Supports any tip percentage from 0% (no-tip cultures) to 30% or more, and can handle bills split among 2 to 20+ people. Ideal for group dining, travel abroad, and service industry tipping norms.
The VAT Calculator handles both directions of VAT calculation: adding VAT to a net (ex-VAT) price to find the gross price, and removing VAT from a gross (VAT-inclusive) price to find the net price. Enter your amount and set the VAT rate for your country — common rates include 20% in the UK, 19% in Germany, 23% in Poland, 25% in Norway, 10% in Korea (부가가치세), and 10% in Japan (消費税). The tool is used by businesses for invoice preparation, by consumers for understanding the tax component in a listed price, and for inter-country price comparison. VAT applies at each stage of the supply chain in most countries, but the consumer ultimately bears the full tax — making the add/remove calculation essential for accurate pricing.