How to calculate your age
To calculate an age, subtract the birth year from the as-of year. If the as-of date falls earlier in the calendar year than the birthday, subtract one more. That gives the number of completed birthdays — the value most legal and administrative systems treat as "age."
Two framings are worth distinguishing. Full years counts only completed birthdays and is what drives legal thresholds such as voting, licensing, or retirement eligibility. Exact age keeps the remainder and expresses it as years, months, and days — useful for anniversaries, medical records, and precise birthday projection.
This calculator shows both. The primary number is the exact age; the "Full years" cell in the total-units card is the completed-birthday count.
Calculating exact age — years, months, and days
Exact-age arithmetic follows the same borrowing pattern as long subtraction, but with calendar-aware month lengths. Take a concrete example: birth date November 15, 2006, as-of date March 10, 2026.
- Subtract years: 2026 − 2006 = 20.
- Check the birthday: March 10 is earlier in the year than November 15, so subtract one year. Running total: 19 years.
- Count complete months since the last birthday: from November 15, 2025 to February 15, 2026 is three complete months. Running total: 19 years, 3 months.
- Borrow days for the partial month: February 15, 2026 to March 10, 2026. Because March 10 falls before the 15th, we borrow from February's day count. 2026 is not a leap year, so February has 28 days. Days elapsed = 28 − 15 + 10 = 23 days.
Final answer: 19 years, 3 months, 23 days.
Quick check
You were born on November 15, 2006. What is your exact age on March 10, 2026?
Age on any past or future date
Most age calculators treat "today" as a silent, hidden anchor. This one lets you pick any as-of date. Switch to the Any date tab above to enter a specific calendar date — past or future.
Past example: someone born on June 1, 1980 on September 11, 2001. Subtract years: 2001 − 1980 = 21. September 11 falls after June 1, so no year deduction. Running total: 21 years. Months and days: 3 months, 10 days. Full answer: 21 years, 3 months, 10 days.
Future example: someone born on November 15, 2006 on their 40th birthday. Same date each year: 40 years, 0 months, 0 days on November 15, 2046.
This is useful for historical records, legal-age checks for a specific date, birthday projections, and genealogy research.
Leap years and February 29 birthdays
February 29 appears only every four years (with an exception every 400 for leap centuries). In non-leap years, conventions disagree on whether the anniversary falls on February 28 or March 1.
This calculator treats February 28 as the anniversary in non-leap years, following the convention codified in the UK Births and Deaths Registration Act 1953 and most US state statutes. A leap-day birthday still increases age by exactly one year each anniversary, whether or not the calendar shows February 29.
Chronological age in professional contexts
Chronological age — the calendar-only elapsed time since birth — is the baseline most professional assessments use. It is distinct from biological age (a physiological measure) and developmental age (used in pediatric and psychological testing).
Practitioners rely on chronological age in several settings:
- Pediatric development. Growth-chart percentiles, vaccination schedules, and milestone screenings are indexed to chronological age at the time of measurement.
- Psychometric assessment. IQ norms and developmental test scores are keyed to the subject's chronological age at test date — which is why assessment publishers like Pearson and the Gesell Institute publish dedicated chronological-age tools.
- Legal and administrative thresholds. Voting, licensing, consent, and retirement eligibility all turn on completed years.
- Genealogy. Computing someone's age on a specific historical date from a known date of birth.
Why do age calculators sometimes disagree?
Small disagreements between age calculators usually come from counting conventions, not arithmetic errors:
- Some tools count the birth date as day 1 (inclusive); the standard is to count it as day 0 (exclusive).
- Some approximate "total months" as days ÷ 30 rather than counting calendar months.
- Some mis-handle February 29 birthdays in non-leap years.
This calculator uses exclusive-birth-day counting, calendar-accurate month lengths, and the leap-year convention documented above.
How old someone is by birth year
Calculated for June 13, 2026
| Birth year | Current age |
|---|---|
| 2025 | 0–1 years |
| 2024 | 1–2 years |
| 2023 | 2–3 years |
| 2020 | 5–6 years |
| 2015 | 10–11 years |
| 2010 | 15–16 years |
| 2008 | 17–18 years |
| 2007 | 18–19 years |
| 2005 | 20–21 years |
| 2000 | 25–26 years |
| 1995 | 30–31 years |
| 1990 | 35–36 years |
| 1985 | 40–41 years |
| 1980 | 45–46 years |
| 1975 | 50–51 years |
| 1970 | 55–56 years |
| 1965 | 60–61 years |
| 1960 | 65–66 years |
| 1955 | 70–71 years |
| 1950 | 75–76 years |
| 1945 | 80–81 years |
| 1940 | 85–86 years |
| 1935 | 90–91 years |
| 1930 | 95–96 years |
| 1926 | 99–100 years |
Frequently asked questions
How accurate are age calculators?
Our calculator uses calendar-accurate arithmetic with leap-year handling — results should be correct to the day. Small disagreements with other tools usually come from different counting conventions rather than arithmetic errors. The "Why do age calculators sometimes disagree?" section above documents exactly which conventions we use, so you can reproduce or cross-check the result.
Why do age calculators give different results?
Different tools count differently. Some include the birth date as day 1 (inclusive); the standard convention excludes it (day 0). Some approximate "total months" by dividing days by 30, which is inaccurate. Some mis-handle February 29 birthdays in non-leap years. We document our conventions on this page so the result is verifiable.
Can I calculate age on a past or future date?
Yes. Switch to the "Any date" tab above and pick any as-of date — past or future. This is the core flexibility of this calculator. Example: if you were born on June 1, 2000, you will turn 50 on June 1, 2050. Legal-age checks, historical records, and birthday projections all work the same way.
What happens if my birthday is February 29?
In leap years, your anniversary is February 29. In non-leap years, this calculator rolls the anniversary to February 28 — following common legal conventions. Your age still increases by exactly one year each anniversary. If you prefer March 1 as the non-leap-year anniversary, simply subtract one day from the "days" output on those years.
What is the difference between exact age and full years?
Full years is the count of completed birthdays — the value most legal and administrative systems use. Exact age breaks the remainder into months and days: "19 years, 3 months, 23 days" shows 19 completed birthdays plus 3 months and 23 days since the last one. The calculator shows both — the big number at the top is the exact age; the "Full years" label in the totals card is the completed-birthday count.