Age Calculator
Find your exact age in years, months and days, plus your total days lived, next birthday countdown, and more.
Full Breakdown
Age Calculator UK
Our Age Calculator works out your exact age in years, months and days from your date of birth, along with useful extras like your total days lived, a countdown to your next birthday, the day of the week you were born on, and your star sign. You can also calculate someone’s age as of any date, past or future, not just today.
How to Use the Age Calculator
- Enter your date of birth using the date picker.
- Choose the date to calculate your age as of. This defaults to today, but you can pick any date on or after your date of birth — useful for working out how old you’ll be on a specific future date.
- Results update automatically as you change the dates, or click Calculate Age to refresh manually.
- Use Copy Results to copy a plain-text summary, or Print for a printable version.
How Your Exact Age Is Worked Out
The calculator compares your date of birth with the date you’re calculating your age as of, and breaks the difference down into whole years, whole months, and remaining days. It also converts the total time elapsed into other useful units: total months, total weeks, total days, and approximate total hours and minutes.
| Metric | How It’s Calculated |
|---|---|
| Years, months, days | Calendar difference between date of birth and the “as of” date |
| Total days lived | Number of whole calendar days between the two dates |
| Total weeks lived | Total days ÷ 7, with the remainder shown separately |
| Total months lived | (Years × 12) + remaining months |
| Next birthday | Next occurrence of your birth month and day on or after the “as of” date |
| Star sign | Based on your date of birth using standard Western zodiac date ranges |
Calculating Age As Of a Different Date
By default, the calculator works out your age as of today, but you can change the second date to see your age (or someone else’s) on any other date. This is useful for working out your age at a wedding, an exam, a retirement date, or any milestone in the past or future.
Important Assumptions
- Calculations use calendar dates only, not exact birth times, so results are accurate to the nearest day.
- Total hours and total minutes lived are approximate figures derived from full days, since exact birth time isn’t collected.
- The date of birth must be on or before the “calculate age as of” date.
- If your birthday falls on 29 February, your next birthday is shown as 1 March in years that aren’t leap years, since 29 February doesn’t exist in those years.
- Star signs are based on standard Western (tropical) zodiac date ranges and are included for interest only.
Frequently Asked Questions
How is my exact age calculated?
Your exact age is calculated by comparing your date of birth with today’s date (or any date you choose), and breaking the difference down into whole years, whole months, and remaining days.
How many days have I been alive?
Total days lived is calculated as the number of calendar days between your date of birth and the date you are calculating your age as of. This calculator shows this figure, along with the equivalent in weeks, months, hours and minutes.
Can I calculate my age on a future or past date?
Yes. Change the “calculate age as of” field to any date on or after your date of birth to see your age at that point, or use the “Set as of to today” button to return to today’s date.
How is my next birthday countdown worked out?
The calculator finds the next occurrence of your birth month and day on or after the date you’re calculating from, then counts the number of days until that date.
What happens if I was born on 29 February?
In non-leap years, a birthday of 29 February is treated as falling on 1 March for the purposes of the next birthday countdown, since 29 February does not exist in those years.
How accurate is this age calculator?
The calculator is accurate to the nearest calendar day. It does not account for your exact time of birth, so total hours and minutes lived are approximate figures based on full days only.