Calculators
Tax, mortgage, BMI, date, unit converters and more
Tax Calculator
Calculate individual income tax with social insurance
Mortgage Calculator
Compare equal-installment and equal-principal payments
Interest Calculator
Deposit interest and compound interest calculation
Kinship Calculator
Figure out kinship terms — your holiday helper
Date Calculator
Days between dates, countdown, business days
Age · Zodiac · Sign
Age, Chinese zodiac and constellation from your birthday
BMI Calculator
BMI calculation and health assessment
Unit Converter
Length, weight, area, temperature, base conversion
Currency Exchange
Common currency exchange rates
Uppercase Amount
Convert numbers to Chinese uppercase (for invoices)
World Clock
Time zones of major cities and time conversion
Scientific Calculator
Trigonometric, logarithmic and power scientific calculator
Percentage Calculator
Percentage: share, change rate, discount
ID Card Lookup
Validate Chinese ID numbers, parse region and birthdate
Pomodoro Timer
25-min focus + 5-min break pomodoro timer
Stopwatch Countdown
Stopwatch and countdown timer with lap recording
Roman Numerals
Convert between Arabic and Roman numerals
AA Bill Splitter
Split bills: total, tip, discount, rounding rules, per-person share at a glance
Due Date Calculator
Estimate due date from last menstrual period or ovulation day, show current week
Retirement Age Calculator
Calculate retirement age under China 2025 gradual delay policy
Temperature Converter
Celsius / Fahrenheit / Kelvin / Rankine conversion
Social Insurance
Calculate social insurance contributions by city / base
Base Converter
Any-base conversion: binary / octal / decimal / hex
Byte Converter
Bit / Byte / KB / MB / GB / TB / PB storage conversion
Disk Partition
Partition capacity calculator, actual usable space