Everyday Calculators

A 20% tip on a $50 bill is $10, for a $60 total — the kind of arithmetic most people do on a phone at the table. Your exact age works the same way: subtract your birth date from today, carrying months and days, which is the identical calendar logic behind "how many days until my flight" or "how many weeks between two dates." Once you see that connection, a handful of tools covers dozens of daily questions.

The 27 tools here divide into four clusters. Age and dates — your exact age in years, months and days, the date a set number of days from now, and days or weeks between any two dates. Time — add and subtract hours and minutes, convert between time zones, and total up a weekly time card. Money — tip splitting, bill splitting, and quick percentage checks. Countdowns — days until a deadline, a birthday, or the last day of school, with the option to split the tab after you celebrate.

Each tool shows its working so you can verify the result rather than just trust it. No sign-up, no ads between you and the answer. Pick a calculator below — most-used ones appear first, then the full list in alphabetical order.