Age Calculator
Age is counted in complete calendar years, then complete months from the year anniversary, then remaining days. Each anniversary is clamped to the last valid day of its month. Total days exclude the target day. Hours are modeled days × 24, not elapsed local-clock hours across daylight saving changes. Weeks are complete groups of seven days; months are complete calendar months.
Proleptic Gregorian dates without a time zone. February 29 anniversaries use February 28 in non-leap years. The next birthday is strictly after the target date.
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Method and limits
Age is counted in complete calendar years, then complete months from the year anniversary, then remaining days. Each anniversary is clamped to the last valid day of its month.
Proleptic Gregorian dates without a time zone. February 29 anniversaries use February 28 in non-leap years. The next birthday is strictly after the target date.
Total days exclude the target day. Hours are modeled days × 24, not elapsed local-clock hours across daylight saving changes. Weeks are complete groups of seven days; months are complete calendar months.
Both dates are required; impossible dates and a birth after the target are rejected. This is a calendar model, not a legal age determination.
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About Age Calculator
Age is counted in complete calendar years, then complete months from the year anniversary, then remaining days. Each anniversary is clamped to the last valid day of its month.
2000-01-01 → 2020-01-01: 20 years, 0 months, 0 days; 7305 total days.
2023-01-31 → 2023-03-01: 0 years, 1 month, 1 day; 29 total days under the month-end clamp.
Proleptic Gregorian dates without a time zone. February 29 anniversaries use February 28 in non-leap years. The next birthday is strictly after the target date.
Use Cases
How to use
Enter your birth date and the date on which to measure your age.
Read the calendar breakdown, aggregate totals and days to the next birthday.
Pro Tips
- Proleptic Gregorian dates without a time zone. February 29 anniversaries use February 28 in non-leap years. The next birthday is strictly after the target date.
- Total days exclude the target day. Hours are modeled days × 24, not elapsed local-clock hours across daylight saving changes. Weeks are complete groups of seven days; months are complete calendar months.
Frequently Asked Questions
Proleptic Gregorian dates without a time zone. February 29 anniversaries use February 28 in non-leap years. The next birthday is strictly after the target date.
The weekday is the Gregorian weekday of birth. Zodiac is the conventional Western sun-sign date range, without birth time or location; it is an informational label.