Age Calculator — How Old Am I Exactly?

How the Age Calculator Works

Our age calculator determines your exact age by counting the years, months, and days between your date of birth and the current date (or any date you specify). It handles all the complexities of date arithmetic including varying month lengths (28, 29, 30, or 31 days), leap years, and century boundaries.

The calculation follows common convention: your age increases by one year on your birthday each year. Months are counted from the same day of each month, and remaining days are counted from the last matching day. For example, someone born on 31 January would be considered one month older on 28 February (or 29 February in a leap year).

UK Age Milestones

In the United Kingdom, certain ages unlock specific legal rights and responsibilities. Here are the key milestones:

Leap Years Explained

Our calendar uses leap years to keep in sync with the Earth's orbit around the sun, which takes approximately 365.2422 days. Without leap years, the calendar would drift by about one day every four years, eventually causing summer to fall in December. The rules are:

• A year is a leap year if it is divisible by 4
• Except for years divisible by 100 (century years), which are NOT leap years
• Except for years divisible by 400, which ARE leap years

So 2024 was a leap year (divisible by 4). 1900 was NOT a leap year (divisible by 100 but not 400). 2000 WAS a leap year (divisible by 400). The next leap year is 2028.

Born on 29 February?

People born on 29 February (a "leapling") only have their actual birthday once every four years. In non-leap years, most countries treat 1 March as their legal birthday for age-related purposes, though some use 28 February. In the UK, a leapling born on 29 February 2000 would legally turn 18 on 1 March 2018.

Fun Age Facts

• A 30-year-old has lived approximately 10,957 days (or 10,958 if they have experienced 8 leap years)
• Your 1 billionth second alive occurs at approximately age 31 years and 8 months
• At age 35, you have spent roughly 12 years sleeping (assuming 8 hours per night)
• The average UK life expectancy is currently about 81 years (79 for men, 83 for women)
• The oldest verified person ever was Jeanne Calment of France, who died at 122 years and 164 days

UK State Pension Age

The UK State Pension age is one of the most important age-related thresholds for retirement planning. The current State Pension age is 66 for both men and women. Planned changes include:

• 2026 to 2028: Increase from 66 to 67
• 2044 to 2046: Planned increase from 67 to 68 (subject to government review)

You can check your personal State Pension age using the government's tool at gov.uk. Your State Pension age determines when you can start receiving the State Pension, which is currently worth up to £221.20 per week (full new State Pension, 2025/26).