Age Calculator

The Age Calculator tells you how old a person is in completed years, months and days, either today or on any other date you pick. Alongside that it lists the same span as total months, weeks, days and hours, and counts down to the next birthday. Most people reach for it when an exam form, a job notice or a school admission rule asks for age "as on" a fixed date.

What to fill in and what you get back

There are two date fields. Date of birth is required. Age on date (optional) is where a cut-off date goes; leave it empty and the calculator measures up to today. The second date can be in the past (how old was Dadi at her wedding?) or in the future (how old will I be on next year's exam date?). Press Calculate age and the result panel shows:

• Your age as years, months and days, the figure most forms want.
• Total months: completed years × 12 plus the leftover months.
• Total weeks: total days divided by 7, with any part-week dropped.
• Total days and Total hours, where hours are simply days × 24.
• Next birthday in, counted from the "age on" date when you filled one, otherwise from today. On the birthday itself it reads Today.

A date of birth later than the second date gives an error rather than a negative age.

How the years, months and days are worked out

The calculator first counts the whole months between the two dates, stepping forward one month at a time from the date of birth. When a step lands on a day that month does not have, it stops at the month's last day, so 31 January plus one month is 28 February (29 in a leap year). The days left over become the day figure, which therefore never goes negative, and the months are split into years and months. Total days is simply the exact count of calendar days between the two dates.

Worked example

Date of birth 20 May 1990, age on 15 October 2026:

1. Whole months: 436 monthly steps from 20 May 1990 reach 20 September 2026. A 437th step would land on 20 October 2026, after the target date.
2. Years and months: 436 = 36 × 12 + 4, so 36 years and 4 months.
3. Days: from 20 September to 15 October 2026 is 10 days to the end of September plus 15 days of October, or 25 days.
4. Result: 36 years, 4 months, 25 days.

The other lines follow from the same dates: 436 total months, 13,297 total days, 13,297 ÷ 7 = 1,899.57 shown as 1,899 weeks, and 13,297 × 24 = 3,19,128 hours. The next birthday, 20 May 2027, is 217 days after 15 October 2026.

For a month-end birthday such as 31 January 1999 measured to 1 March 2026, 325 whole months reach 28 February 2026, as February has no 31st, and one more day gives 27 years, 1 month, 1 day.

Age limits on exam and job notices

Recruitment and entrance notices usually say something like "must have attained 21 years and must not have attained 25 years as on 1 August 2026". The date that matters is the one printed in the notice, not the day you apply, so type it into the Age on date field.

Suppose a candidate was born on 15 August 2001. Measured to 1 August 2026 the calculator shows 24 years, 11 months, 17 days, and the next birthday line reads 14 days. The candidate has not yet attained 25 on the cut-off date, so the upper limit is met, even though they turn 25 two weeks later. Someone born on 1 August 2001 shows exactly 25 years, 0 months, 0 days: their 25th birthday falls on the cut-off itself, so they have attained 25 and miss an "under 25" limit.

Many notices also print the eligible birth-date window ("born not earlier than … and not later than …"), and comparing your date of birth with it is the final word. Relaxations for reserved categories, ex-servicemen or persons with disabilities are added to the upper limit by the notice, so add those years yourself.

Birthdays on 29 February

The month-end rule also decides leap-day birthdays. For someone born on 29 February 2004, the age count completes the new year on 28 February in years without a 29th: 21 years, 11 months, 29 days on 27 February 2026, then exactly 22 years on 28 February, and 22 years, 0 months, 1 day on 1 March.

The Next birthday in line follows the same rule, so it reads 1 day on 27 February 2026, Today on 28 February and 364 days on 1 March. In a leap year such as 2028 the birthday is 29 February itself. Conventions for leap-day births vary, so if an office names a particular date, its rule wins.

Uses for the totals, and where the tool stops

The Total days line is handy for milestones: the 10,000th day of life arrives at roughly 27.4 years of age (10,000 ÷ 365.25). For a pet, the dog age calculator applies its own conversion.

The calculator works with calendar dates only. It has no field for time of birth, so the hours figure is whole days multiplied by 24. For a gap unrelated to a birthday, such as a notice period, use the date difference calculator.