Age Calculator
Exact age in years, months and days, plus a countdown to the next birthday.
How this calculator works
Pick a date of birth and, if you like, a date to measure to. You get the precise age in years, months and days, the total days lived and how long until the next birthday.
The Age Calculator gives an exact age in years, months and days from a date of birth, rather than the rough whole-years figure most of us carry around. Pick your date of birth and, optionally, a date to measure up to — useful for forms, eligibility checks, or working out how old someone was on a particular day. The tool also shows the total number of days lived and a countdown to the next birthday.
Counting age precisely is trickier than it looks because months have different lengths and leap years add an extra day every four years. The calculator handles those calendar quirks for you, so the years-months-days breakdown is always consistent with the actual calendar rather than an arithmetic shortcut.
Use it for filling in official forms that ask for an exact age, for calculating the age gap between two people, for counting down to a milestone birthday, or simply out of curiosity about how many days you have been alive.
Everything runs in your browser as you type — nothing is stored or sent to a server. Results are estimates for general guidance and should not replace advice from a qualified professional.
Frequently asked questions
How is exact age calculated?
The calculator counts the full years between the birth date and the target date, then the remaining full months, then the remaining days — accounting for the different lengths of months and leap years.
Can I calculate age on a past or future date?
Yes. Enter a date of birth and any target date, past or future, and the tool returns the exact age on that day.
What is the countdown to the next birthday?
It is the number of days from the target date until the next anniversary of the date of birth.
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