Age Calculator

Calculate an Exact Age — Down to the Day

Enter a date of birth and get the precise age in years, months, and days, measured as of today or any past or future date you choose. The same result also breaks the span down into total months, weeks, days, hours, minutes, and seconds, tells you which weekday you were born on, and counts down to the next birthday. A second mode finds the exact gap between any two dates, including full weeks and the number of business days.

Everything is computed on your device using the browser's own calendar — nothing is uploaded, there's no sign-up, and there are no usage limits. The math is done on whole dates rather than timestamps, so results never drift by a day for people in evening or negative-offset timezones, and total-day counts are measured against UTC midnights so a daylight-saving change can't throw them off.

One honest caveat: because the calculator works from calendar dates and not a specific clock time, the hour, minute, and second totals assume midnight-to-midnight. They're exact multiples of a whole day, not a live tick from your exact moment of birth.

Common Use Cases

• Eligibility checks: Confirm someone meets an age requirement — a license, a discount, a benefit, or a school cutoff — as of a specific date.
• Forms and applications: Fill in an exact age in years and months for medical intake, immigration, or insurance paperwork.
• Milestones and birthdays: See how many days until the next birthday and what day of the week it lands on, so you can plan ahead.
• Notice periods and deadlines: Use days-between to count the exact span from a start date to a due date, contract end, or 30/60/90-day deadline.
• Project and leave planning: Get the business-day count (Monday–Friday) between two dates, separate from weekend days.
• Pets, anniversaries, and records: Track how old a pet is, how long since an anniversary, or the age of a document in weeks and months.

Privacy: The age calculator runs entirely in your browser. The dates you enter never leave your device, are never sent to a server, and are not stored anywhere.