An age calculator turns your date of birth into your age in years, months, days, weeks and hours. You enter one date and immediately see how long you have been alive.

What separates one calculator from another is how it counts. Anything based on average years drifts by several days across a lifetime. This one uses the real calendar, including every leap year and every month of 28 to 31 days.

The number of weeks is the number of days lived divided by seven. For someone born on August 24, 1990 that is 1,888 full weeks and 0 days on October 30, 2026.

We never round up. A week only counts once it is complete; the remaining days are shown separately, so you can see both add up.

days lived ÷ 7 = whole weeks, with the remainder as loose days

The number of whole months is how many times the day of your birth has come round since you were born. For August 24, 1990 that is 434 on October 30, 2026.

That is not the same as dividing your days by 30. Months run from 28 to 31 days, so the counter ticks over on the day of the month you were born — not somewhere in between.

complete years × 12 + whole months since your last birthday

The number of hours is the number of whole calendar days times 24. For August 24, 1990 the counter stands at 317,184 hours on October 30, 2026.

This is the only value that is an approximation, and there is a reason: we never ask for your time of birth. Someone born at 11pm had lived just one hour on their first day. Quoting a more precise figure would pretend to know something we do not.

days lived × 24

The weekday of your birth is fixed in the calendar and never changes. Someone born on August 24, 1990 was born on a Friday.

There is a pattern to it: the same date shifts one weekday each year, and two after a leap year. That is why your birthday falls on your birth weekday again roughly once every seven years.

Your next birthday is the next time your day and month come round. For August 24, 1990 that is August 24, 2027 — 298 days away, turning 37.

If this year’s birthday has already passed, the count runs on to next year. If it is today, the counter sits at zero and the countdown is over.

next date carrying your day and month − today

Anyone born on 29 February has no real birthday in three years out of four. We use 1 March, the same line Dutch law takes for reaching an age.

There is no worldwide agreement on this: some countries settle on 28 February, others on 1 March. It makes no difference to the number of days lived — that simply counts on. It only affects the question of when you turn a year older.