Calculate the exact age between two dates
This is a free age calculator between two dates. Give it a start date and an end date and it returns the precise age, or difference, between them — expressed in years, months and days, and also as the running totals in months, weeks, days, hours, minutes and seconds. It is the tool to reach for when you need an exact figure rather than a rough “about thirty years”.
The calculation runs in your browser the moment both dates are valid, so there is no button to press and nothing is uploaded. Use the “Copy shareable link” button to send anyone the exact calculation.
How to calculate age between two dates
- Enter the start date. This is usually a date of birth, but it can be any historical or past date.
- Enter the end date. Use today, a future date, or another past date.
- Read the result. The age between the two dates appears instantly and updates as you change either date.
Age difference between two dates, explained
The “age between two dates” is simply the elapsed time from the first date to the second — the same thing as the age difference or duration between them. The calendar makes this harder than it looks: months vary from 28 to 31 days and a leap day is added every four years. This calculator counts complete years first, then whole months, then the remaining days using real calendar dates, so the breakdown is exact and always reconciles to the total number of days.
What you can work out with it
- Exact age on a specific date: use the birth date as the start date and any date as the end date to see how old someone was, or will be, on that day.
- Age difference between two people: enter each person's date of birth to see the gap between them.
- Length of service or membership: a start date and end date give precise tenure for HR, pensions or contracts.
- Time since an event: how long since a wedding, graduation, or a historical date.
- Project and milestone spans: the exact duration between a start and a deadline.
Common calculations
| You want to know… | Start date | End date |
|---|---|---|
| Your age today | Your date of birth | Today |
| Your age on a future birthday or event | Your date of birth | That future date |
| Age gap between two people | Older person's DOB | Younger person's DOB |
| Length of employment | Start of service | Last working day |
| Time since a historical event | The event date | Today |
Frequently asked questions
How do I calculate age between two dates?
Enter a start date and an end date above; the exact age between them appears immediately.
What is the age difference between two dates?
It is the elapsed time between them, shown here as years, months and days plus full totals.
Can I use a future date?
Yes — either date may be in the past or the future.
Can I find someone's age on a specific date?
Yes. Put the birth date as the start date and the specific date as the end date.
Does it handle leap years?
Yes, automatically — it uses true calendar dates.
Is it free?
Completely free, with no sign-up and no limits.