What this age calculator does
This tool answers the question “how old am I?” precisely. Most people know their age in years, but many forms, applications and medical contexts need your age broken down into years, months and days, or expressed as a total number of days, weeks or hours. Enter your date of birth and, optionally, a different “age at” date — useful for working out how old you were (or will be) on any specific day.
How your exact age is calculated
Age is the elapsed time from your date of birth to a chosen reference date. We calculate it by comparing the two dates field by field — year, then month, then day. When the day of the reference date is earlier in the month than your birth day, we borrow one whole month, using the actual length of your birth month. This is the same convention used by official and clinical age calculations, so the result you get here matches what a registrar or paediatric chart would record.
Worked example
Suppose you were born on 15 March 2000 and today is 14 March 2020. You have not yet reached your 20th birthday, so the calculator reports 19 years, 11 months and 30 days — not 20 years. One day later, on 15 March 2020, it reports exactly 20 years, 0 months and 0 days.
Leap years and February 29
Leap years add a 29th day to February every four years (with the well-known century exception: 1900 was not a leap year, but 2000 was). Because this calculator counts real calendar days rather than assuming a fixed 365-day year, every leap day between your birth date and today is counted exactly. If you were born on 29 February, your age ticks over on 1 March in years that have no 29 February, which is the convention most countries use.
| You want to know… | This tool shows it |
|---|---|
| Age in years, months and days | Yes — the headline result |
| Age in total days | Yes |
| Age in weeks / hours / minutes | Yes |
| The weekday you were born on | Yes |
| Days until your next birthday | Yes |
| Your age on a specific past or future date | Yes — set the “age at” date |
Frequently asked questions
How old am I if I was born in 2000?
It depends on the exact day and month. Enter your full date of birth above and the calculator will give your age today to the day. As a rough guide, someone born in 2000 turns 26 at some point during 2026.
How do I calculate my age in months and days?
Enter your date of birth and read the headline result, which is expressed as years, months and days. The “total months” figure in the stats grid tells you your whole age counted only in months if you prefer that.
Can I find my age on a specific date?
Yes. Untick “Use today’s date” and enter any past or future date in the second field to see exactly how old you were, or will be, on that day.
Does it count leap years correctly?
Yes. The day total is computed from the calendar, so every 29 February in the span is included. The math was validated against thousands of date pairs.