📐 Everyday Tools
Practical everyday calculators and converters — unit conversion (length, weight, temperature, volume), date and time calculators, percentage and fraction tools, sales tax and tip calculators, salary estimators, and age calculators. The kind of quick math you reach for during daily life.
⏱️ Duration Converter
Convert duration to seconds and back. Convert seconds to hours, minutes, human readable (1h 30m), colon notation (01:30:20), and ISO 8601 (PT1H30M20S).
🎂 Age Calculator
Calculate exact age in years, months, and days from a birth date. Find days until next birthday, total days lived, and date-to-date intervals.
💲 Tip Calculator
Calculate tip and split a bill between any number of people with a tip percentage slider and per-person totals.
📚 ISBN Validator
Validate ISBN-10 and ISBN-13 checksums, convert between formats, and identify the registration group (language/country) and GS1 prefix.
BMI Calculator
Calculate your Body Mass Index (BMI) from height and weight in metric or imperial units, with category, healthy weight range, and ideal body weight.
IBAN Validator
Validate IBAN numbers, check the country, length, and mod-97 checksum. Format, mask, and explain IBAN structure.
Number to Words Converter
Convert numbers to English words — cardinal, ordinal (first, second…), and currency (dollars & cents)
Timezone Converter
Convert any time across world timezones instantly. Compare UTC, local, and 15+ major cities.
Unit Converter
Convert between units: length, weight, temperature, area, volume, speed, digital storage, time, energy, pressure. Real-time.
VIN Decoder
Decode any 17-character Vehicle Identification Number (VIN) — manufacturer, country, model year, assembly plant, serial, with ISO 3779 check-digit verification.