Free Age Calculator
Calculate your exact age in years, months, and days. Find days between any two dates, or count down to any future event.
Your Age
36 years, 3 months, 22 days
Born January 1, 1990
13,261
Total Days
1,894
Total Weeks
435
Total Months
252
Days to Birthday
All calculations run in your browser. No data is sent to any server.
Frequently Asked Questions
How is exact age calculated?+
Exact age is calculated by counting complete years from the date of birth to today, then the remaining complete months, then the remaining days. The calculation accounts for leap years and varying month lengths automatically.
How many days old am I?+
The total number of days since your birth date is simply the difference in calendar days between your birthday and today. Use the "Calculate Age" tab — your age in total days is shown alongside your age in years and months.
Does the age calculator account for leap years?+
Yes. The calculator uses JavaScript's native Date object, which correctly handles all calendar irregularities including leap years, varying month lengths, and daylight saving transitions.
What is the difference between age and days between dates?+
"Age" specifically calculates how old someone is by comparing their birth date to today. "Days between dates" is more general — it gives the exact number of calendar days between any two dates you specify, regardless of whether they are birth dates.
How do I calculate someone's retirement date?+
Use the "Days Until" tab and enter the date when the person turns the retirement age (e.g., 65). First use the age calculator to find their exact birth year and month, then calculate forward.
Can I calculate age on a specific past or future date?+
Yes. In the "Days Between Dates" tab, enter the birth date as your start date and any other date as the end date. The result shows the age on that specific date.
Why Exact Age and Date Calculations Matter
Calculating an exact age sounds simple but has real edge cases: leap years, the varying number of days in each month, and whether "1 year old" means 365 or 366 days depending on the year. This calculator uses JavaScript's native Date object to handle all calendar irregularities correctly, giving you an exact answer in years, months, and days — the same way a legal or medical document would report an age.
Practical uses: legal, financial, and medical contexts
Exact age calculations matter in more contexts than birthdays. Insurance premiums are often age-banded — crossing a birthday can change your rate. Retirement eligibility, Medicare enrollment (age 65), Social Security benefits (62 for early, 67 for full retirement age), and Required Minimum Distributions from IRAs (age 73) all have precise age requirements. Contract terms often specify durations in days. Warranty periods, lease agreements, and loan terms are all date-based calculations. Use the "Days Between Dates" tab to calculate exactly how many days remain on any time-bound obligation. For loan repayment planning, the Loan Calculator handles full amortization schedules.
How leap years affect age calculations
If you were born on February 29 (a leap day), your legal birthday in non-leap years is typically treated as March 1 in most jurisdictions (though some use February 28). A person born on February 29, 2000 turned 24 years old in 2024 — the first leap year birthday they could celebrate since 2016. Between those two leap years, their "birthday" technically falls on March 1. This calculator always uses the calendar date you enter, so February 29 birthdays display correctly when checking a leap year date.
Days between dates: project and contract planning
The "Days Between Dates" mode is useful for any time-bounded calculation: how many days until a contract expires, how many days of vacation have elapsed, how long until a deadline, or the duration of a subscription. It counts calendar days (not business days). For planning purposes, a 90-day contract is 90 calendar days regardless of weekends and holidays. The result also shows the full period in weeks and the breakdown in years, months, and days for human readability.