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Calculator library · 14
Investing, loans & FIRE—start with today's number
Use any consistent currency unit.
US-specific tools are clearly marked.
01Investing
Compound Interest
Project a lump sum and monthly contributions with compound growth, including total contributions and investment gains.
02FIRE
FIRE Target
Calculate the monthly contribution needed to reach a financial-independence target by a chosen date.
03Stocks
Average Stock Price
Combine two stock purchases to calculate the weighted average price, total shares and total amount invested.
04Stocks
Loss Recovery
Find the gain required to recover from an investment loss and return to the original value.
05Saving
Deposit Interest
Estimate gross interest, tax, net interest and maturity value for a lump-sum deposit or monthly savings plan.
06Loans
Loan Payment
Estimate payments and total interest for amortized, equal-principal and interest-only balloon loans.
07Work & Pay
Overtime Pay
Estimate weekly overtime pay under the federal Fair Labor Standards Act 1.5x rule for hours worked beyond 40 in a week.
08Work & Pay
Self-Employment Tax
Estimate federal self-employment (Social Security and Medicare) tax on net freelance or 1099 profit.
09Housing
Real Estate Area
Convert square feet, square meters, acres and pyeong for overseas listings, and separately convert commercial usable square footage to rentable square footage using a load factor.
10Housing
Jeonse Conversion
Convert a Korean lease's deposit and monthly rent (wolse) into an equivalent full-deposit jeonse figure, using South Korea's legal cap or a typical market rate.
11Work & Pay
Income Percentile Rank
Enter your annual income and compare where it ranks in South Korea, Japan, the United States, the United Kingdom, Germany, Hong Kong, Singapore and Malaysia, using each country's official income-distribution statistics.
12Work & Pay
Net Worth Percentile Rank
Enter your net worth (assets minus debts) and compare where it ranks against official household net-worth statistics from South Korea, Japan, the United States, the United Kingdom, Germany and Singapore.
13Currency
Exchange Rate
Convert Korean won to and from JPY, USD, AUD, EUR, offshore Chinese yuan (CNH) and HKD using Korea Eximbank's latest official exchange-rate data.
14Tax & Estate
Federal Estate Tax
Estimate U.S. federal estate tax using the 2026 US$15 million basic exclusion, Form 706 deductions and the unified transfer-tax rate schedule.
PERSONAL FINANCE WORKBENCH2026 EDITION
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Practical guidesPut the formulas
View all English guides →Put the formulas
into real situations
For travel, tuition and transfers to Korea
How Korean Won Exchange Rates Work
Read a KRW exchange-rate quote correctly, estimate a conversion in either direction, and understand why your card or bank total differs from the published base rate.
8 min read →Financial independence, translated into a numberFind Your FIRE Number
Estimate a FIRE target from annual spending, then test how long your current savings plan may take to reach it.
8 min read →Why the second decade can matter more10 vs 20 Years of Compounding
Compare monthly investing over 10 and 20 years and see when growth begins to contribute more than new cash.
7 min read →Small rate, large lifetime differenceThe Cost of 1% More Interest
Compare monthly payment and total interest on a 30-year loan at 3%, 4% and 5%.
7 min read →From hourly wage or 1099 income to what lands in your accountOvertime & SE Tax
Compare a 45-hour workweek under the federal FLSA overtime rule with the 15.3% self-employment tax on freelance profit — two common gaps between gross pay and take-home pay.
7 min read →From an overseas listing's pyeong to a U.S. lease's load factorSquare Footage Isn't Universal
Convert an overseas listing's size into square feet you understand, see why a U.S. home's square footage isn't measured the way Korea's is, and learn what a commercial lease's 'load factor' actually adds to your rent.
8 min read →A uniquely Korean lease calculation, explained for foreign rentersKorea's Jeonse Conversion Rate
Learn the formula behind Korea's deposit-to-rent conversion rate, see where the legal cap does and doesn't apply, and work through a real ₩150 million deposit / ₩1.6 million rent example.
8 min read →Reading your place in the income distribution, correctlyIncome Percentile, Explained
Why mean and median income differ, how banded government data gets turned into a percentile rank through interpolation, and where each of the 8 countries' official income statistics come from.
9 min read →Reading your place in the wealth distribution, correctlyNet Worth Percentile, Explained
Why every country tracks net worth by household rather than by individual, how negative net worth shows up in official data, and where each of the 6 countries' household wealth statistics come from.
8 min read →A trend is more useful than a single rankReading Growth Percentiles
A US-focused guide to measuring a school-age child consistently, interpreting WHO 2007 height and BMI percentiles, and knowing the calculator's limits.
7 min read →Same unit, different measurement methodDXA vs InBody Percentiles
Understand ALM, ALMI and SMI before comparing a DXA or InBody result with Korean, US or Chinese adult reference distributions.
8 min read →A U.S.-specific estate planning guide2026 Federal Estate Tax Guide
Work through a US$20 million U.S. estate, the 2026 federal exclusion, deductions, portability and the unified 18%–40% transfer-tax schedule.
9 min read →The Firessem standardRead the conditions
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