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Tools

Every tool, grouped by kind. Star the ones you use often.

Refunds & cancellation fees

Fitness, education & childcare

Refund and cancellation calculators with reference letters

Gym Membership Refund Calculator (Korea)NEW

Works out the refund for cancelling a Korean gym membership under the Fair Trade Commission's dispute-resolution standard.

Academy Tuition Refund Calculator (Korea)NEW

Refund for leaving a Korean private academy under the Enforcement Decree of the Academy Act.

Postpartum Care Center Refund Calculator (Korea)NEW

Refund for cancelling a Korean postpartum care center contract, before or after entry.

Study Room Refund Calculator (Korea)NEW

Works out the refund when you quit a Korean registered study room (dokseosil) early or the operator closes, under the Hagwon Act enforcement decree Annex 4.

Refund Policy Notice Maker (Korea)NEW

Generates a refund policy notice for Korean gyms, academies, study rooms and postpartum care centers based on the consumer dispute resolution standards. Korean only.

Travel, weddings & leisure

Refund and cancellation calculators with reference letters

Travel Cancellation Fee Calculator (Korea)NEW

Cancellation fee for a Korean package or domestic tour under the standard terms,.

Wedding Hall Cancellation Calculator (Korea)NEW

Penalty for cancelling a Korean wedding hall contract under the standard terms.

Korean Hotel / Pension Booking Cancellation Refund CalculatorNEW

Works out the refund for cancelling a Korean hotel, pension or campsite booking under the Fair Trade Commission's dispute-resolution standard (lodging).

Show Ticket Cancellation Refund Calculator (Korea)NEW

Works out the refund for cancelling a Korean concert, musical or play ticket under the Fair Trade Commission's dispute-resolution standard.

Golf Course Booking Cancellation Penalty Calculator (Korea)NEW

Works out the penalty and deposit refund for cancelling a Korean golf course booking under the Fair Trade Commission's dispute-resolution standard and the standard golf course terms.

Home, moving & rentals

Refund and cancellation calculators with reference letters

Water Purifier Rental Cancellation Fee Calculator (Korea)NEW

Works out the early-termination fee for a Korean rental contract (water purifier etc.) under the Fair Trade Commission's dispute-resolution standard.

Moving Contract Cancellation Penalty Calculator (Korea)NEW

Works out the penalty or compensation when a Korean moving contract is cancelled before the move date, under the Fair Trade Commission's dispute-resolution standard.

Korean Real Estate Brokerage Fee Calculator (Cap and Overcharge)NEW

Works out the legal cap on a Korean real estate agent's commission for housing, officetels and other property, and how much of an amount already paid exceeds it.

Lease Renewal Notice Period and 5% Cap Calculator (Korea)NEW

Works out the window for renewal notices on a Korean residential or commercial lease and the 5% rent increase cap. Korean only.

Cars & mobility

Refund and cancellation calculators with reference letters

Rental Car Cancellation Refund Calculator (Korea)NEW

Works out the refund for cancelling a Korean rental-car booking or ending a rental early, under the Fair Trade Commission's dispute-resolution standard and the standard rental terms.

Finance, insurance & funerals

Refund and cancellation calculators with reference letters

Insurance Cooling-off Deadline Calculator (Korea)NEW

Finds the deadline to withdraw a Korean insurance application (the earlier of 15 days after receiving the policy and 30 days after applying) and the 3-month cancellation date.

Funeral Service (Sangjo) Cancellation Refund Calculator (Korea)NEW

Works out the minimum refund when you cancel a Korean prepaid funeral-service (sangjo) installment contract early, under the Fair Trade Commission's notice.

Late Payment Interest Calculator (Korea)NEW

Calculates late payment interest on an unpaid sum by date: 5% civil, 6% commercial or an agreed rate, switching to the 12% litigation rate after the complaint is served. Korean only.

Loan Repayment Schedule Calculator (Korea)NEW

Builds a payment schedule for equal-payment, equal-principal and bullet loans with grace periods and prepayment fees. Korean only.

Telecom, subscriptions & shopping

Refund and cancellation calculators with reference letters

Gift Certificate & Gifticon Refund Calculator (Korea)NEW

Works out the refund for a Korean gift certificate or mobile gifticon within 7 days of purchase, for an unused balance, or after expiry, under the Fair Trade Commission's dispute-resolution standard.

Work, money & tax

Work, pay & job applications

Overtime and severance, payslips, freelancer tax, and character counters for applications

Overtime, Holiday Pay and Severance Calculator (Korea)NEW

Calculates Korean overtime, night and holiday premiums, weekly holiday allowance and severance pay. Korean only.

Payslip and Social Insurance Calculator (Korea, 2026 rates)NEW

Calculates Korean social insurance deductions, net pay and employer contributions for 2026. Korean only.

Freelancer 3.3% Withholding and Income Tax Estimator (Korea)NEW

Calculates the 3.3% withholding on freelance payments in Korea and estimates the annual income tax settlement. Korean only.

Take-Home Pay Calculator (Korea)

Work out your monthly take-home pay in Korea after the four social insurances and income tax for 2026, with every deduction itemised.

Minimum Wage Calculator (Korea)

Convert Korea's 2026 minimum hourly wage of KRW 10,320 and your contracted weekly hours into a daily, weekly and monthly wage (209-hour basis) and check whether your rate falls below it.

Annual Leave Calculator (Korea)

Work out the annual leave accrued under article 60 of the Korean Labor Standards Act, what is left, and the unused-leave allowance from an hourly or monthly wage.

Hourly, Monthly and Annual Pay Converter (Korea)

Convert hourly, monthly and annual pay into each other with paid weekly holidays included, and see the monthly take-home pay after insurance and income tax.

Character & Byte Counter (Korean NEIS, Resumes)NEW

Paste text to get character counts with and without spaces, plus byte counts under three rules side by side: NEIS (Korean school records), UTF-8 and EUC-KR (job-site style). Enter a limit such as 1500 bytes or 500 characters to see what is left or where you went over. The limits are editable.

Tax & business

VAT, year-end tax settlement, margins and quotes

VAT Calculator (Korea)

Turn a VAT-exclusive supply value or a VAT-inclusive total into the 10% VAT, the supply value and the total, laid out in the lines a Korean tax invoice needs.

Year-End Tax Refund Calculator (Korea)

Enter your yearly salary and the tax already withheld to estimate the refund or the extra tax due, recalculated with the 2026 income tax rates.

Margin and Selling Price Calculator

Enter unit cost, extra costs, platform fee and target margin to get a selling price that does not lose money, plus profit and fee per unit.

Quote Maker

Enter your business, the client and the items with quantity and unit price to get a quote with supply value, 10% VAT and total, ready to print or save as PDF.

Money

Percentages, discounts, bill splitting and savings interest

Percentage Calculator

Find X% of an amount, what percent one number is of another, or the percent change between two values, with the formula shown.

Discount Calculator

Turn a list price and percent off into a sale price, with a second discount and VAT, or work back to the original price.

Split Bill Calculator

Divide a bill per person, add a tip, round each share up to a clean amount, or settle item by item.

Savings Interest Calculator

Gross interest, withholding tax and after-tax payout for a lump-sum deposit or monthly savings, on simple or compound interest.

Other tools

Developer tools

Quick converters and checkers for everyday development

Cron Expression Parser: Next Run Times in KST and UTCNEW

Explains a 5-field cron expression and lists the next 10 run times in Korea Standard Time (KST) and UTC, with the equivalent expression for a server running on UTC.

JWT Decoder (expiry in KST)NEW

Paste a JWT to see its header and payload as colored JSON, with exp, iat and nbf converted to UTC and Korea Standard Time plus the time left before expiry. Can also verify HS256, HS384 and HS512 signatures.

Subnet & CIDR CalculatorNEW

Enter an IPv4 address with a prefix length (/24) or subnet mask to get the network and broadcast addresses, usable IP range and host count, with binary working and a subnet split table.

Unix Timestamp Converter (KST)NEW

Convert a Unix timestamp (epoch time) to Korea Standard Time (KST) and UTC, or a KST date back to seconds and milliseconds. It tells seconds from milliseconds by digit count and shows the current timestamp live.

Designer tools

Colour, spacing and asset helpers for design work

Color Contrast Checker (WCAG and KWCAG)NEW

Enter a text and a background color to get the WCAG 2.2 contrast ratio and AA/AAA pass or fail for normal text, large text and UI components. Explains the 4.5:1 rule used by Korea's KWCAG 2.2 and suggests the nearest passing color when a pair fails.

px rem pt mm Unit ConverterNEW

Convert px, rem, em, pt, pc, in, cm, mm and Q in one go. Set the root font size and viewport width for rem and vw, and work out print pixel dimensions for A4, A5 and B5 at 72 to 600 dpi (including 96 dpi, the CSS reference).

Everyday calculators

Days between dates, age, time and hours worked, area and unit conversion, BMI

Date Calculator

Count the days between two dates, or add and subtract days, weeks, months and years and see the resulting weekday.

Time Calculator

Time difference between two clock times, adding and subtracting hours and minutes, and worked hours minus breaks — as HH:MM and decimal hours.

Age Calculator

Enter a date of birth to see your exact, calendar-year and Korean age, the days to your next birthday and the days lived.

Unit & Ratio Calculator

Solve A : B = C : ?, scale a ratio by N, and convert length, mass and volume units with exact standard factors.

Pyeong Calculator

Convert pyeong to square metres and back (1 pyeong = 400/121 m²), with one-tap chips for common apartment sizes.

BMI Calculator

Body mass index from height and weight, with a category and healthy weight range, using the Korean 18.5 / 23 / 25 cutoffs.

Photo

Compress, merge, blur and censor photos, ID photos

Image Compressor

Reduce a photo to a target size (20–3,000 KB, e.g. 200 KB) or a max width, in bulk, and save as JPEG, WebP or PNG.

Merge Photos

Combine photos into one PNG or JPEG, stacked, side by side or in a 2–4 column grid, with spacing and background colour.

Blur & Pixelate Photo

Rub over a photo to hide faces, names, phone and card numbers with a mosaic or blur, then save it as a JPG.

Blur Photo Background

Blur a whole photo in one tap, then paint the person or object back into focus by hand. Saves a JPG.

Passport Photo Maker

Crop a photo to passport or ID size (35×45 mm, 30×40 mm) or US visa 2×2 in and save it at the exact 300 dpi pixel size.

Images & QR

Aspect ratios, social image sizes, QR codes and passwords

Change Image Aspect Ratio

Crop a photo to 1:1, 4:5, 3:4, 16:9 and other ratios. Drag to choose the crop, zoom, pick an output width and save a JPG.

Social Media Image Resizer

Crop or pad a photo to the exact size each platform wants: Instagram 1080×1350, YouTube 1280×720, X, Facebook, LinkedIn, TikTok.

QR Code Generator

Turn a URL, text or phone number into a QR code and save it as PNG or SVG. Set the size, colours and error correction.

Password Generator

Create a random password of 8–64 characters from upper, lower, digits and symbols, with an entropy estimate in bits.