Everyday Tools
Age, relationship terms, rent splitting, retirement age and body metrics. Simple formulas with a surprising number of edge cases — leap years, regional conventions, and rules that changed partway through the year you were born.
Where a rule differs by region or by birth date, the tool shows which convention it applied rather than silently picking one.
- Age CalculatorCalculate your exact age in years, months and days from a date and time of birth, with zodiac sign, Chinese zodiac, birthday countdown and age milestones
- China statutory retirement age calculatorWork out your statutory retirement age and retirement month under the gradual delay reform, with flexible early or delayed retirement windows and the minimum years of contributions
- Chinese kinship calculatorWork out Chinese kinship terms from a relationship chain, reverse-lookup a term, and find how two people address each other or their joint term
- Rent and Utility CalculatorCalculate one billing period locally in the browser — enter electricity and water meter readings to get usage, fees and the total, keep extra fees in one place, manage multiple locations and rooms, and export your records
Guides in this category
Common questions
Why do two age calculators disagree by one year?
One is likely using the East Asian nominal-age convention (everyone turns one year older on New Year) instead of completed years since birth.