How to Calculate Your Exact Age (Years, Months, Days)
Knowing your age in whole years is easy, but working out the exact years, months and days is trickier — especially with leap years and different month lengths. Whether you need it for a form, a document, or just curiosity, an age calculator gives you the precise answer instantly.
How age is calculated
Your age is the difference between your date of birth and a chosen date (usually today). The calculation subtracts years, then months, then days, "borrowing" from the larger unit when a value goes negative — just like manual subtraction. This correctly accounts for months of different lengths and for leap years.
Step-by-step: find your exact age
- Open the Age Calculator.
- Enter your date of birth.
- Leave the second date as today, or set it to any date you like.
- Click Calculate to see your age in years, months, days and total days.
Why total days is useful
Besides years and months, the calculator shows the total number of days you've been alive. It's a fun figure and also handy for milestones, anniversaries, or working out durations between two dates.
Frequently Asked Questions
Does it account for leap years?
Yes. The calculation uses real calendar dates, so leap years and varying month lengths are handled automatically.
Can I calculate age between any two dates?
Yes. Just change the second date to whatever you need — it doesn't have to be today.
Why does the number of days in a month vary?
Months have 28–31 days, so the calculator borrows the correct number of days from the previous month when needed for an accurate result.
Is my date of birth stored?
No. The calculation runs in your browser and nothing you enter is saved or uploaded.
Can I use it for pets or events?
Absolutely — enter any start date to find the exact time elapsed since then.
Try the Age Calculator