Age Calculator

How to use

1. Enter the date of birth.
2. Keep "Calculate up to today" checked, or uncheck it to pick any target date.
3. See exact age, totals and the countdown to the next birthday instantly.

Use cases

1. Use case: Plan birthday milestones Calculate exactly how many days until a child turns 10, or how many years, months and days old a person is for a birthday card or anniversary countdown.

2. Use case: Verify age for forms When a form asks for precise age (e.g. insurance or school enrollment), compute the exact age in years, months and days from a birth date instead of rounding.

Practical tips

The result is exact calendar arithmetic — years, months and days — with leap years handled correctly, including the February 29 birthday case. Set the target date to something other than today for questions like 'how old will they be on the contract date'. Age in total days is useful for warranty and trial-period math where months are ambiguous. The calculation is timezone-free: it uses calendar dates, not birth hours. Like every tool on this site, the Age Calculator runs entirely in your browser: the data you enter never leaves your device, nothing is uploaded to a server, and the tool keeps working if your connection drops.

Common mistakes

Calendar arithmetic is exact, so the mistakes are interpretive:

• Forgetting the calculator is timezone-free: it uses calendar dates, so a birth time just after midnight in another zone can legally differ by a day.
• Misreading the years/months/days breakdown as a decimal — 1 year 6 months is not 1.6 years.
• Using total days for anything legal that specifies months; contracts and warranties usually mean calendar months.
• Overlooking the February 29 birthday case: leaplings age on Feb 28 or Mar 1 depending on jurisdiction.

Frequently asked questions