Smart & Fast Tools
For Your Daily Needs
Popular Tools
Hourly Wage Calculator
Calculate part-time wages, holiday allowances, and taxes (3.3%, 4 major insurances) with minimum wage presets.
Salary & Tax Calculator
Estimate net salary, 4 major social insurances, and income taxes for employees and employers.
Currency Converter
Live exchange rates and automatic conversion powered by Open ExchangeRate-API.
Unit Converter
Instant real-time unit converter for length, area, weight, and temperature.
Age Calculator
Calculate international age, Korean official age, Chinese zodiac sign, and milestones.
Military Discharge Calculator
Calculate military discharge date, progress percentage, and promotion dates.
Lunar Calendar Converter
Convert between Solar and Lunar calendars, check leap months, 60-year sexagenary cycle, and traditional holidays.
D-Day & Countdown Calculator
Calculate D-Day countdown, days passed since milestones, anniversaries (100 days, 1 year), and future dates.
Color Picker & Converter
Extract color codes and convert between HEX, RGB, HSL, and CMYK formats.
Base64 Encoder & Decoder
Real-time UTF-8 safe Base64 encoding and decoding tool for developers.
JWT Token Decoder
Client-side secure JSON Web Token (JWT) Header, Payload, and expiration date decoder.
Word & Character Counter
Real-time character count (with/without spaces), byte size, word count, and text manipulation tools.
Split Bill Calculator
Flexible split bill calculator supporting multiple rounds (1st, 2nd, 3rd), custom participants per round, and minimal transaction summary.
Travel Settlement Calculator
Multi-currency travel expense calculator supporting custom exchange rates, full/half/split shares, and minimal money transfer paths.
Famous Quote Explorer
Search & explore inspiring quotes from Eastern & Western thinkers with custom image card export.
Periodic Table of Elements
Interactive 118 chemical elements with real-time temperature state simulation, Bohr orbitals, and chemistry quiz.
Multiplication Table Master
Interactive multiplication tables from 1x1 to 19x19, custom N-dan generator, dot area model, and mental math quiz.
Trigonometry & Unit Circle
Interactive Unit Circle visualizer, sine/cosine/tangent wave graphs, triangle solver, and speed math quiz.
Linear Algebra Studio
Interactive 2D matrix transformation visualizer, determinant, eigenvalues, inverse matrix, vector spaces, and linear equation solver.
Number System Explorer
Interactive hierarchy of numbers (Natural, Integer, Rational, Irrational, Real, Complex) and historical invention motives.
Equations & Inequalities Explorer
Interactive visualizer connecting 1st, 2nd, and 3rd degree polynomial equations to graph x-intercepts, discriminants, and inequalities.
Function & Inverse Concepts
Interactive explorer for function definitions, bijective one-to-one mappings, and the y=x mirror reflection of inverse functions.
Sequences & Limits Explorer
Interactive exploration of term progressions, geometric ratio behaviors, and the true meaning of infinite limits.
Ladder Game
Interactive online ladder draw with toggleable curtain blind, instant tracing, and outcome summary.
Dice Roller
Roll single or multiple virtual dice with instant sum calculation and roll history.
Random Order Picker
Fair random order generator for presentation turns, sequence shuffling, and queue sorting.
Lucky Draw & Raffle
Random raffle and giveaway picker to select fair winners from a custom pool of candidates.
Team Generator
Generate balanced random teams by group count or members per team from custom participant lists.
BMI Calculator
Calculate Body Mass Index (BMI), obesity categories (WHO & Asian-Pacific standards), ideal body weight, and healthy weight ranges.
Heart Rate Zone Calculator
Calculate maximum heart rate and 5 aerobic exercise intensity zones (Zone 1 to Zone 5) using the Tanaka and Karvonen formulas.
Weight Training Wiki
Comprehensive illustrated guide to 880+ gym machines, bodyweight, and free-weight exercises: target muscle anatomy, setup, execution, breathing cues, and rep routines.
FMD Diet Wiki
Complete 5-Day Fasting Mimicking Diet (FMD) database: daily calorie & macro ratios, meal recipes, personalized bodyweight calculator, and 30+ food compatibility ratings.
Workout Log
Set-by-set workout logger for weights, cardio and stretching, monthly calendar with streaks, science-backed split routines, and Weight Training Wiki form guides.
Endocrine Wiki
Step-by-step metabolic schematics: ATP-producing catabolism (glycolysis, TCA, beta-oxidation) and muscle-building anabolism (mTOR, leucine threshold).