Age Calculator

About Age Calculator

Age Calculator works out your exact age in years, months, days — and even total hours — from any birth date. It's handy for forms, eligibility checks, birthday countdowns, or settling the classic 'how old am I in days?' question.

Calculates age based on birthdate Use Age Calculator online for AI tasks with quick examples and copy-ready results.

How to use Age Calculator

1. Open Age Calculator on AltFTool — it loads instantly in your browser.
2. Enter the values you already know.
3. Adjust the options for your scenario.
4. Use the calculated result for comparison or planning.

Why use Age Calculator

• Precise to the day

  Get years, months and days rather than a rounded number.

• Any date range

  Calculate age as of today or any past/future reference date.

• Private by default

  Dates are processed in your browser and never uploaded.

Common use cases

• Confirm an exact age for a job, visa, or pension eligibility form.
• Count down the days to a birthday, anniversary, or milestone.
• Work out the age gap between two people or two dates.

Frequently asked questions

How does the Age Calculator count months and days?

It compares your birth date to the reference date calendar-accurately, accounting for different month lengths and leap years.

Can I calculate age for a future date?

Yes — set any reference date to see how old someone will be on that day.

Is my birth date stored anywhere?

No. The calculation runs entirely in your browser; nothing is sent to a server.