EasyUtil
Calculators, converters, and fun tools — all the utilities you need.
Official Data
Built on NTS tax tables, NHIS insurance rates, and government-published formulas — updated within 7 days of regulatory changes.
100% Private
All calculations run in your browser. No data is collected, stored, or sent to any server. Ever.
Instant Results
No signup, no downloads. Just enter your numbers and get accurate results in seconds — completely free.
💰Finance & Tax (South Korea)
National Pension Calculator (Korea)
Estimate monthly Korean national pension based on income and contribution period.
Take-Home Pay Calculator (Korea)
Calculate net salary after Korean tax and social insurance deductions.
Severance Pay Calculator (Korea)
Estimate severance pay under Korean labor law based on tenure and salary.
Loan Interest Calculator
Calculate monthly repayments for equal principal and interest.
Savings Interest Calculator
Calculate maturity interest and after-tax returns on deposits.
Percentage Calculator
Easily calculate ratios, discounts, and percentages.
Capital Gains Tax Calculator (Korea)
Estimate Korean tax on property sales with long-term holding deductions.
Gift Tax Calculator (Korea)
Calculate Korean gift tax with relationship-based deductions.
Unemployment Benefits Calculator (Korea)
Estimate Korean employment insurance benefits after leaving a job.
Jeonse–Monthly Rent Converter (Korea)
Convert between Korean lump-sum deposit (Jeonse) and monthly rent.
Health Insurance Calculator (Korea)
Calculate Korean national health insurance premium contribution.
Earned Income Tax Credit (Korea)
Estimate Korean earned income tax credit by household type.
Income Tax Calculator (Korea)
Calculate Korean comprehensive income tax and tax due.
Car Registration Tax (Korea)
Calculate Korean vehicle acquisition tax, bond purchase, and stamp duty.
Housing Subscription Score (Korea)
Calculate your Korean housing subscription (cheongnyak) points.
Property Acquisition Tax (Korea)
Calculate Korean property acquisition tax, education tax, and rural special tax.
Car Insurance Calculator (Korea)
Estimate Korean auto insurance premium by vehicle type, driver age, experience, and grade.
Electricity Bill Calculator (Korea)
Calculate your Korean residential electricity bill with tiered progressive pricing, VAT, and power industry fund included.
Latte Factor Calculator
What if you invested your daily coffee money? See how small daily spending grows into a fortune through compound interest.
Real-Time Hourly Wage Counter
Calculate your hourly, per-minute, and per-second wage from annual or monthly salary. Watch your earnings tick up in real time.
Global Income Rank Calculator
Find out where your income ranks globally. See your top percentile, Korean rank, and country comparisons.
Korean Business Registration Number Validator
Validate the format and checksum of a 10-digit Korean business registration number.
Korean Insurance Age Calculator
Calculate the rounded "insurance age" used by Korean insurers, alongside standard Korean age.
⚖️Health
🔄Lifestyle & Utils
Unit Converter
Convert length, weight, and area units in real time.
Character Counter
Count characters and words in real time.
D-Day Calculator
Count days until anniversaries, exams, and events.
GPA Calculator
Calculate your grade point average.
GPA Converter (Korean Scales)
Convert grades between 4.5, 4.3, 4.0 scales and 100-point percentile scores using the standard Korean conversion table.
Age Calculator
Calculate your exact age, zodiac sign, and days until next birthday.
Life Timeline — Visualize Your Life in Weeks
See your entire life as a grid of weeks. Enter your birth date and life expectancy to visualize weeks lived, weeks remaining, and life progress.
Delivery vs Pickup Comparison
Compare delivery and pickup costs including delivery fee, travel cost, and time value.
Decibel Meter (Noise Meter)
Measure ambient noise levels in real time using your microphone. See dB readings and a noise level reference chart.
Screen Ruler (Online Ruler)
Calibrate your screen and measure real cm/inch sizes. Credit card calibration, point-to-point measurement, A4/business card overlays.
Korean Address to English Converter
Convert a Korean address into English following official romanization rules — for international shipping and overseas orders.
Korean Name Hanja Finder
Look up Hanja (Chinese characters) for Korean names by meaning and reading, syllable by syllable.
Korean Name Romanizer
Convert a Korean name into passport-style, common, and hyphenated romanized spellings.
Sexagenary Cycle (Gapja) Calculator
Find a year's position in the 60-year sexagenary cycle, zodiac animal, element, and symbolic color.
Number to Korean Amount Converter
Convert a numeric amount into the Korean reading used in contracts, plus the formal anti-forgery numeral style.
Pyeong ↔ Square Meter Converter
Convert between pyeong and square meters, with a quick-reference table for common apartment sizes.
Cover Letter Character Trimmer
Trim text to a target character count and check counts with/without spaces.
Lunar ↔ Solar Date Converter
Look up Korean lunar calendar dates for ancestral rites, birthdays, and holidays.
Korean Zodiac & Western Zodiac Calculator
Find both the Korean zodiac animal and the Western star sign from a birth date.
Military Discharge Date Calculator
Estimate the discharge date and service progress from an enlistment date and service length.
👶Baby & Parenting
Due Date Calculator
Calculate your estimated due date and pregnancy week.
Baby Feeding Calculator
Calculate the right feeding amount for your baby's weight.
Baby Food Calculator - Stage, Water Ratio & Ingredient Schedule
Enter your baby's birth date for the current weaning stage, porridge water ratio (10:1/7:1/5:1), and a dated ingredient introduction schedule.
Baby Age Calculator
Calculate your baby's age in months and days.
Vaccination Schedule
Check your child's recommended vaccination schedule.
Baby Height & Weight Rank
Just enter the birthday — auto-ranks your baby out of 100 peers by WHO height & weight percentiles.
Baby Sleep Calculator
Enter your baby's birth date to get night/nap sleep needs and today's nap & bedtime schedule based on wake windows.
Baby Height Predictor
Predict your child's adult height from parents' heights.
Baby Name Initial Combiner
Pick a starting consonant to browse candidate Korean baby name syllables, then combine with a surname.
Ovulation & Fertile Window Calculator
Enter the first day of your last period and average cycle length to estimate your ovulation date, fertile window, next period, and suggested pregnancy test day.
Parental Leave Pay Calculator (Korea 2026)
Based on Korea's 2026 rules, enter your monthly ordinary wage and leave length to see your parental leave benefit month by month, with the 100% brackets and caps applied.
Korea Newborn & Childcare Benefit Calculator
Add up the First Meeting voucher, Parental Allowance (age 0 & 1), and Child Allowance to estimate total government support after birth (2026 rules).
Baby Growth & Development Milestone Calculator
Enter the birth date to see age-appropriate milestones (movement, language, cognitive, social), the next goals, and signs that warrant a professional consult. Based on K-DST and CDC 2022.
Baby Head Circumference Rank
Enter birthday and head circumference — auto-ranks your baby out of 100 peers by WHO standards.
🎮Fun & Games
Bubble Wrap
Pop virtual bubble wrap to relieve stress.
Click Counter
Challenge yourself — how fast can you click?
Reaction Time Test
Measure your reaction speed.
Color Match Game
Find the one different color — a color perception test.
Dice Roller
Roll 1–3 dice online.
Number Guessing (Up & Down)
Guess a number between 1 and 100.
Time Guessing Game
Can you guess the time accurately by feel?
Typing Speed Test
Measure your typing speed and accuracy.
Korean Initial Consonant Quiz
Guess the Korean word from its initial consonants (초성) — a popular casual game.
Rock Paper Scissors
Play rock paper scissors against the computer and track your win rate.
Ladder Game (Random Picker)
Fairly assign random outcomes to a group with the classic ladder (Amidakuji) game.
💻IT & Developer Tools
JSON Formatter (Viewer & Validator)
Pretty-print JSON, catch syntax errors instantly, and minify — all in your browser.
Base64 Encoder / Decoder
Encode text to Base64 or decode it back. Full Unicode support, converted instantly in your browser.
URL Encoder / Decoder
Percent-encode URLs and query parameters or decode them back to readable text.
UUID Generator (v4)
Generate up to 100 UUID v4 identifiers at once. Uppercase and no-hyphen options with one-click copy.
Unix Timestamp Converter
Convert Unix timestamps to dates and dates to timestamps. Auto-detects seconds vs milliseconds, live current timestamp.
Regex Tester
Test regular expressions live with match highlighting, capture groups, and flag support — all in your browser.
Hash Generator (SHA-256 & more)
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes of any text instantly, entirely in your browser.
Color Code Converter (HEX·RGB·HSL)
Convert between HEX, RGB, and HSL color codes with live preview and a color picker.
JWT Decoder
Decode a JWT token's header and payload and check expiry — processed in your browser, never sent to a server.
Password Generator (Secure Random)
Generate secure passwords with cryptographic randomness. Configurable length and character types with strength indicator.
Text Diff Checker
Compare two texts line by line and highlight added and removed lines — processed entirely in your browser.
Case Converter (camelCase·snake_case)
Convert text between camelCase, snake_case, kebab-case, and 11 naming conventions at once.
Cron Expression Parser
Translate cron expressions into plain language and see the next 5 run times.
Lorem Ipsum Generator
Generate Lorem Ipsum and Korean dummy text by paragraphs, sentences, or words for design mockups.
IP Subnet Calculator (CIDR)
Calculate network address, broadcast, subnet mask, and host range from an IP address and CIDR prefix.
Korean/English Keyboard Typo Converter
Recover text typed without switching input language, based on the 2-beolsik Korean keyboard layout.
Why EasyUtil?
EasyUtil was created because everyday calculations shouldn't require specialized knowledge. Whether you're a salaried worker trying to understand your paycheck deductions, a new parent tracking your baby's growth milestones, or a student calculating your GPA before graduation — you deserve accurate answers without complexity.
Every calculator on this site is built using official data sources: the National Tax Service's simplified wage income tax tables, the National Health Insurance Service's premium rates, and WHO growth standards for pediatric tools. When tax rates change or insurance premiums are adjusted, we update the affected calculators promptly so your results always reflect current standards.
All calculations run entirely in your browser — your salary figures, health data, and personal information never leave your device. No account creation, no app installation, no hidden fees. Just the answers you need, when you need them.