Age Calculator
Work out your age or someone else's age in years, months, days, and totals.
Inputs
Result
Enter values on the left and select Calculate to see the result here.
What the Age Calculator does
- Computes your age breakdown (years, months, days) for a target date.
- Also provides total days, weeks, and months elapsed.
How to use the Age Calculator
- Enter a date of birth.
- Optionally choose a target date (defaults to today).
- Click Calculate to see the age breakdown.
Formula / methodology used
- Uses calendar-aware year/month/day differences (not a simple days ÷ 365 approximation).
- Validates that the target date is not before the birth date.
- Official, legal, immigration, employment, or insurance deadlines may use specific rules that differ from this general calendar calculation.
Example calculation
Born 2000-01-15, target 2026-03-17.
- From 2000-01-15 to 2026-01-15 = 26 full years
- From 2026-01-15 to 2026-03-15 = 2 full months
- From 2026-03-15 to 2026-03-17 = 2 days
Result: The age breakdown is 26 years, 2 months, and 2 days, plus total elapsed days, weeks, and months.
Common mistakes and limitations
- Different organisations may define deadline age, anniversary dates, inclusive days, or cut-off times differently.
- Do not rely on this page for legal, immigration, insurance, benefit, pension, school, or employment eligibility decisions.
Important note
This calculator is a general date maths tool and is not official legal, administrative, immigration, employment, or insurance advice.
Age Calculator FAQs
Why do months and days vary?
Months have different lengths, so a calendar-based calculation is more accurate than using averages.