Calculate exact age in years, months, and days
Determine exact chronological age and countdown to your next birthday. 100% private, leap-year accurate, and computed instantly in your browser.
How it works
Select birth date
Pick your date of birth using the date selector or manual date entry.
Choose target date
Optionally select a custom target date, or leave it set to today.
View exact breakdown
See your age broken down into years, months, days, total days, and next birthday countdown.
It is processed on your machine
This is the kind of content people are most nervous about pasting into a website. Here nothing is transmitted: your browser reads the input, the tool works on it in the tab, and the result is handed straight back. Close the tab and it is gone.
- Opened from your disk by your browser — not sent anywhere first.
- Held in the tab while the tool works, then dropped.
- Saved to your device by your browser, not by a link to a server.
- Closing the tab clears the working copy completely.
- No account, so nothing is ever attached to an identity.
- No tracking of what you worked on or what was inside the file.
There is no queue and no retention policy to read. Whatever you pasted is released the moment the tab closes. See how your data stays inside the tab for the full picture, or follow the DevTools check to verify your file never leaves.
What people use it for
Formats & limits
What this tool accepts, what it produces, and what it will never ask you for.
- Input
- The formats listed above
- Output
- Set in the controls above
- Maximum file size
- Set by your device, not by a plan
- Files per run
- One at a time
- Sign-up required
- None
- Watermark
- Never added
- Works offline
- Yes, once the page has loaded
- Supported browsers
- Any current Chrome, Edge, Firefox or Safari
When something goes wrong
Invalid input stops with a plain message that points at the exact problem, rather than a spinner that never finishes.
The content is not in the shape this tool expects. Check for a missing bracket or an extra character and try again.
Why not an online service
A hosted version of this tool means your input is transmitted to a server you have no relationship with. Removing that step removes the whole category of risk.
A typical upload site
This tool
Questions
How is leap year accounted for?
The calculator accurately accounts for February 29th in leap years and varying month lengths (28, 29, 30, or 31 days) using standard chronological date arithmetic.
Can I calculate age on a past or future date?
Yes. Change the 'Age on date' selector to calculate your age at any historical moment or milestone in the future.
Is my birth date private?
Completely. Your birth date is processed locally in your browser sandbox and is never transmitted or stored anywhere.
What if the date entered is in the future?
The calculator handles future dates gracefully and indicates when the selected birth date has not yet occurred.
Is there a file size limit?
No fixed limit is imposed by the tool. The practical ceiling is how much memory your device has free, because the whole job runs inside this browser tab.
Does it work without an internet connection?
Yes, once the page has loaded. Nothing is fetched while you work, so a dropped connection does not interrupt a run.