Age Calculator
Find your exact age in years, months, and days from your date of birth — plus your age in total weeks, days, and hours, and a countdown to your next birthday.
Your age is
— years, — months, — days
Your age in other units
How age calculators work
This tool calculates the exact time between your date of birth and a target date (today by default). It counts full years first, then the remaining full months, then the leftover days — the same way age is counted in everyday life. Because it uses real calendar dates, it automatically accounts for months of different lengths and for leap years.
Age in years, months, and days
Most people give their age in whole years, but the precise figure includes the months and days since your last birthday. The headline result shows all three, while the table below breaks your age down into total months, weeks, days, hours, and minutes — useful for milestones and fun facts.
Counting down to your next birthday
The calculator also shows how many days remain until your next birthday, based on today's date, so you can plan ahead.
Using it for any two dates
You're not limited to "today" — change the second date to any date to measure the time between two dates, such as an anniversary or a future milestone.
Age in different units
Ever wondered how old you are in hours or minutes? The table under the calculator breaks your age down into months, weeks, days, hours, and minutes. It can be fun for birthdays, anniversaries, or just satisfying curiosity.
Age and metabolism
As you age, your metabolism tends to slow, partly because muscle mass declines and partly because activity levels can drop. If you are curious how your age affects daily calorie needs, try the BMR calculator. It uses age along with height, weight, and sex to estimate your resting metabolism.
Common age-related questions
- Does metabolism slow with age? Yes, largely due to muscle loss and lower activity. Resistance training helps maintain metabolic rate.
- At what age does metabolism peak? Metabolism is usually highest in late teens to early twenties, then gradually declines.
- Can I boost my metabolism at any age? Building muscle through strength training increases resting calorie burn at any age.
- How does muscle loss affect metabolism? Each kilogram of muscle lost reduces resting calorie burn by roughly 15–25 kcal/day.
Related calculators
BMR Calculator
Estimate your resting metabolism based on age, sex, height, and weight.
TDEE Calculator
Find your total daily energy expenditure including activity.
Frequently asked questions
How do I calculate my age?
Enter your date of birth and the date you want to calculate your age on (today by default). The calculator works out the exact difference in years, months, and days.
How old am I exactly?
Your exact age is the time elapsed since your birth date. This tool shows it in years, months, and days, and also as total months, weeks, days, hours, and minutes.
How is age calculated in years, months, and days?
The calculator subtracts your birth date from the target date, borrowing days and months where needed (using the actual length of each month), so the result matches how age is counted in everyday life.
How many days until my next birthday?
The calculator shows a countdown to your next birthday based on today's date — handy for planning celebrations.
Does the age calculator account for leap years?
Yes. Because it uses real calendar dates, leap years (including February 29) are handled automatically.
Can I calculate age between two dates?
Yes. Change the second date from today to any date to find the age or time difference between any two dates.
Is the age calculator free?
Yes, completely free with no sign-up. All calculations run privately in your browser.
How does age affect my metabolism?
Metabolism tends to decline with age because of muscle loss and hormonal shifts. Use the <a href='/bmr-calculator/'>BMR calculator</a> to see how your basal metabolism changes over time.
What is my age in dog years?
A rough rule of thumb is one dog year ≈ 7 human years, but it varies by breed and size. Large dogs tend to age faster than small breeds.