How to use the age calculator
- Choose the date of birth – type the year or use the calendar icon.
- Leave Age at the Date of as today, or pick any past or future date.
- Press Calculate. You get the exact age in years, months and days, the same age in months, weeks, days, hours, minutes and seconds, the next birthday, and the weekday you were born on.
How age is calculated
Age is counted in completed units: a year counts only once the birthday has passed, and a month only once the same day of the month has been reached. The calculator works in three steps:
- Years – the number of birthdays that have passed.
- Months – full months since the last birthday, counted from the same day number each month.
- Days – the days left over since the last month was completed.
- Last birthday: May 15, 2026 → 36 years
- May 15 → October 15, 2026 → 5 months
- October 15 → October 18 → 3 days
Age: 36 years, 5 months and 3 days (13,305 days in total).
- The 2026 birthday is still to come, so the last one was August 28, 2025 → 30 years
- August 28, 2025 → February 28, 2026 → 6 months (March 28 hasn't arrived)
- February 28 → March 10 → 10 days
Age: 30 years, 6 months and 10 days.
Age by year of birth in 2026
A quick lookup if you only know the birth year. The age depends on whether this year's birthday has already passed.
| Born in | Age before birthday in 2026 | Age after birthday in 2026 |
|---|---|---|
| 2020 | 5 | 6 |
| 2015 | 10 | 11 |
| 2010 | 15 | 16 |
| 2005 | 20 | 21 |
| 2000 | 25 | 26 |
| 1995 | 30 | 31 |
| 1990 | 35 | 36 |
| 1985 | 40 | 41 |
| 1980 | 45 | 46 |
| 1975 | 50 | 51 |
| 1970 | 55 | 56 |
| 1965 | 60 | 61 |
| 1960 | 65 | 66 |
| 1955 | 70 | 71 |
| 1950 | 75 | 76 |
Age in other units
To compare ages across units, these are the averages for one year in the Gregorian calendar (365.2425 days, because of leap years):
| Unit | In 1 year | In 10 years |
|---|---|---|
| Months | 12 | 120 |
| Weeks | 52.18 | 521.8 |
| Days | 365.24 | 3,652.4 |
| Hours | 8,765.8 | 87,658 |
| Minutes | 525,949 | 5,259,492 |
| Seconds | 31,556,952 | 315,569,520 |
The calculator itself doesn't use averages – it counts the actual calendar days between the two dates, including every February 29.
Different ways of counting age
| System | How it works | Where it's used |
|---|---|---|
| International age (this calculator) | 0 at birth; +1 on each birthday | Almost everywhere, and in law and official documents |
| East Asian age reckoning | 1 at birth; +1 for everyone at the Lunar New Year | Traditional use in China and nearby cultures. South Korea moved official and legal use to international age in 2023. |
| Age next birthday | The age you will turn at your next birthday | Some forms, surveys and insurance quotes |
| Age nearest birthday | Rounds to whichever birthday is closer | Some life insurers |
When the start date is at the end of a month
Months have different lengths, so a period that begins on the 28th–31st can be read two ways. From February 28 to March 31, 2022:
| Method | Reasoning | Result |
|---|---|---|
| Same day number (used here) | Feb 28 → Mar 28 is one month, plus 3 days | 1 month 3 days |
| End of month to end of month | Both dates are the last day of a month | 1 month |
Both are reasonable. This calculator always uses the first method, so the same pair of dates always gives the same answer.
Calculate age in Excel or Google Sheets
With the date of birth in cell A2:
| You want | Formula |
|---|---|
| Age in whole years | =DATEDIF(A2, TODAY(), "Y") |
| Months after the last birthday | =DATEDIF(A2, TODAY(), "YM") |
| Days after the last full month | =DATEDIF(A2, TODAY(), "MD") |
| Age in days | =TODAY() - A2 |
Excel's "MD" option can give odd results near month ends, which is one reason to double-check important ages here.
Birthdays on February 29
- A leap-day birthday occurs only in leap years: years divisible by 4, except century years not divisible by 400 (2000 was a leap year, 2100 won't be).
- In common years the age goes up on March 1 by this calculator's counting. Many people celebrate on February 28 instead, which is the date shown for the next birthday.
- Legal rules for the exact day vary by country, so check local rules for official deadlines.
Frequently asked questions
How old am I if I was born in 1996?
You are 29 if your birthday in 2026 is still to come, and 30 once it has passed. For the exact age in years, months and days, enter your full date of birth above.
How many days old am I?
Enter your date of birth and the result shows the exact number of days, counting every leap day. As a rough guide, multiply your age in years by 365.25.
How do I calculate my age in months?
Multiply the completed years by 12 and add the months since your last birthday. The calculator shows this as “In months”, for example 437 months 3 days.
Can I calculate the age between any two dates?
Yes. Put the earlier date in “Date of Birth” and the later date in “Age at the Date of”. For weekday and weekend counts in a period, use Days Between Dates.
How old will I be on a future date?
Change “Age at the Date of” to that date – for example a wedding, a retirement date or January 1 of a future year.
Does the time of day or time zone change the result?
No. The calculator counts whole calendar days, so the result is the same in every time zone.