Financial guides
built around real numbers
Each guide starts with a practical situation, shows the assumptions, and links directly to the calculator so you can replace the example with your own numbers.
01How to Convert Korean Won: Base Rates, Bank Spreads and the Amount You Actually Pay
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
02How Much Do You Need to Retire Early? A Practical 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
0310 Years vs 20 Years of Compound Growth: What Changes?
Compare monthly investing over 10 and 20 years and see when growth begins to contribute more than new cash.
7 min read
04What Does a 1 Percentage Point Higher Mortgage Rate Really Cost?
Compare monthly payment and total interest on a 30-year loan at 3%, 4% and 5%.
7 min read
05Overtime Pay and Self-Employment Tax: What Non-Salaried Income Really Nets You
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 read061,200 Square Feet, 33.7 Pyeong: Why Overseas Listings Don't Compare Directly
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 read07What Is Korea's Jeonse Conversion Rate? A ₩150 Million Deposit, ₩1.6 Million Rent Example
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 read08Mean vs. Median, Explained: How Your Income Percentile Rank Is Actually Calculated
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 read09Why Net Worth Statistics Are Always Household-Level (And What That Means for Your Rank)
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
10How to Read a Child Growth Percentile Without Chasing the 50th
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 read11DXA vs InBody: What a Muscle-Mass Percentile Actually Means
Understand ALM, ALMI and SMI before comparing a DXA or InBody result with Korean, US or Chinese adult reference distributions.
8 min read
122026 Federal Estate Tax: The US$15 Million Exclusion, Form 706 and a Worked Example
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