Guide Collection
Practical guides on unit conversion, overseas shopping, development, and electronics · 24 guides
Daily
Unit converters, image tools, and date/time utilities for everyday use
Pyeong to Square Meters Conversion Guide
4 minA complete reference for converting between pyeong (a Korean area unit) and square meters, including a handy conversion table.
Inches to cm Conversion Guide
3 minLearn how to easily convert between inches and centimeters for TV screens, monitor sizes, smartphone displays, and shoe sizes.
kg, lbs & Temperature Unit Guide
3 minA practical guide to converting between pounds and kilograms, and between Fahrenheit and Celsius for everyday use.
How to Reduce Image File Size with Minimal Quality Loss
4 minPractical tips for resizing and compressing images for blogs, online stores, and social media.
JPEG vs PNG vs WebP: Which Format Should You Use?
4 minA comparison of common image formats to help you choose the right one for photos, illustrations, and screenshots.
UTC vs KST: Understanding Timestamps and Time Zones
4 minHow UTC and KST differ, how to read Unix timestamps, and how to interpret server log times.
Travel & Overseas
Currency exchange, overseas shopping costs, GPS coordinates, and time zones
How to Calculate Total Cost for International Shopping
5 minA step-by-step guide to calculating the full cost of overseas purchases, including shipping, customs, and taxes.
Reducing Foreign Transaction Fees on Your Credit Card
4 minHow foreign transaction fees work, how exchange rates are applied, and practical tips for minimizing costs.
Understanding Import Duties and Tax-Free Allowances
4 minA general guide to personal import duty thresholds and how import taxes are calculated.
GPS Coordinate Formats: DD, DMS, and UTM Explained
4 minUnderstand the differences between GPS coordinate formats and when to use each one.
Time Zone Differences and Daylight Saving Time Tips
3 minHow to calculate time zone differences and what to watch out for with daylight saving time.
Smart Travel Money Tips: Getting the Best Exchange Rate
4 minA comparison of airport exchange booths, local ATMs, and travel cards to help you get the best deal.
Developer
Number base conversion, color tools, text encoding, and code page utilities
UTF-8 vs CP949: Why Korean Text Gets Garbled
5 minWhy Korean characters appear as gibberish in Windows environments, and how to fix encoding issues.
Reading Hex Logs: A Practical Debugging Guide
5 minHow to interpret hex dumps from serial communication, packet logs, and binary files.
Binary and Hexadecimal Basics for Debugging
4 minHow computers represent numbers, the relationship between binary and hex, and common patterns in development.
HEX, RGB, HSL: Color Model Differences and When to Use Each
4 minA comparison of the three most common color representation systems in CSS and design tools.
Color Accessibility: Contrast Ratios and Text Readability
4 minHow WCAG contrast ratio requirements work and how to choose accessible color combinations.
Data Size Units Explained: KB, MB, GB, TB and Beyond
3 minThe difference between binary (1024) and decimal (1000) data size definitions, and understanding download speed units.
Electronics
Ohm's law, LED resistors, ADC conversion, and electrical unit tools
LED Resistor Calculation: Circuit Basics
5 minHow to calculate the series resistor needed to safely connect an LED, with practical wiring examples.
Voltage Dividers: How They Work and How to Calculate Them
4 minThe principle behind using two resistors to produce a lower voltage, with calculation examples.
ADC Basics: Understanding Analog to Digital Conversion
5 minKey concepts in ADC — resolution, reference voltage, and sampling rate — explained clearly.
How to Read Resistor Color Codes: 4-Band and 5-Band
4 minA complete guide to reading resistor color bands, including tolerance markings.
Battery Life Estimation: Why Actual Life Differs from Rated Capacity
4 minHow to estimate battery life from capacity (mAh) and current draw, and why real-world performance may differ.
Ohm's Law in Practice: V, I, R Calculation Examples
4 minThe fundamentals of Ohm's law and how to apply it in real circuit calculations.