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Calculates age based on birthdate
About this tool
Calculates age based on birthdate
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.
Open Age Calculator on AltFTool — it loads instantly in your browser.
Enter the values you already know.
Fine-tune the options to match your scenario.
Read the result and use it in your planning or reporting.
Get years, months and days rather than a rounded number.
Calculate age as of today or any past/future reference date.
Dates are processed in your browser and never uploaded.
It compares your birth date to the reference date calendar-accurately, accounting for different month lengths and leap years.
Yes — set any reference date to see how old someone will be on that day.
No. The calculation runs entirely in your browser; nothing is sent to a server.