Age Calculator
Find your exact age in years, months and days — plus your next birthday.
Your age is more than a single number, and this calculator shows every angle of it. Enter your date of birth and it works out your exact age in years, months, and days, then converts your whole life into total months, days, and hours. It also tells you which day of the week you were born on and counts down the days to your next birthday. Everything is calculated in your browser, so your date of birth never leaves your device.
How the exact age is worked out
Rather than dividing total days by 365, the calculator counts calendar-accurately: it subtracts the day, month, and year separately and borrows across months when needed. If the current day is earlier in the month than your birth day, it borrows the correct number of days from the previous month before reducing the month count — the same way you'd work out an age on paper. That's why it stays right across months of different lengths and across leap years, which a simple day-count would get slightly wrong.
The totals and extras
Alongside your precise age, you get your lifespan expressed as a running total of months, days, and even hours — the kind of figures that make fun milestones, like spotting when you'll reach 10,000 days old. The next-birthday countdown looks ahead to the coming occurrence of your birth date and reports how many days remain, and the birth-weekday lookup names the day you were born. All of it updates from the single date you enter.
Frequently Asked Questions
Does it handle leap years correctly?
Yes. Because it counts calendar months and days rather than dividing by a fixed 365, it accounts for leap years and the different lengths of months, so the years-months-days figure stays accurate.
How is the total number of months calculated?
It multiplies your completed years by twelve and adds the extra completed months, giving the total number of whole months you have lived — useful for tracking a baby's age or long anniversaries.
Can I use it to count down to a birthday?
Yes. It finds the next time your birth date occurs and shows how many days away it is, so you can see exactly how long until your next birthday.
Is my date of birth stored?
No. The calculation happens entirely in your browser and nothing you enter is uploaded or saved.