Age Calculator: Determine Years, Months, Days & Zodiac Sign from Birthday
Enter your birthdate, press “Calculate,” and the tool returns your exact years-months-days, total days lived, next-birthday countdown, and zodiac sign—everything you need for paperwork or fun. Around 385,000 babies are born each day worldwide (UN ICEF, 2023), so precise age data matters.
Age Calculator
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How to use the tool
Select your birthdate: tap the calendar and pick the day you were born.
Example A: 5 May 1995
Example B: 30 January 2010
Press “Calculate.” The script instantly measures the gap between today and your birthdate.
Read the results panel: you’ll see age in years, months, days; total days lived; days to next birthday; and your zodiac sign.
Check the pie chart: it visualises the share of years, months and days in your life span.
Behind-the-scenes formulas
Years $$\ rac{\text{current year} – \text{birth year}}{1}$$
Months $$\text{current month} – \text{birth month}$$ (subtract one year and add 12 if negative)
Days $$\text{current day} – \text{birth day}$$ (borrow previous month’s length if negative)
Total days lived $$\left\lfloor\ rac{\text{today} – \text{birthday}}{86\,400\,\text{s}}\right\rfloor$$
Days to next birthday $$\left\lceil\ rac{\text{next birthday} – \text{today}}{86\,400\,\text{s}}\right\rceil$$
Worked example: 5 May 1995 → 18 September 2024
Years: 2024 − 1995 = 29
Months: 9 − 5 = 4
Days: 18 − 5 = 13
Exact age: 29 years, 4 months, 13 days
Zodiac sign: Taurus
Quick-Facts
The Gregorian calendar uses a 400-year cycle and averages 365.2425 days (US Naval Observatory, 2023).
Leap years occur every 4 years except centurial years not divisible by 400 (ISO 8601:2004).
Earliest supported date in modern JavaScript: 1 January 1970 UTC (ECMA-262, 2023).
There are 12 zodiac signs, each spanning 30-31 days (Royal Astronomical Society, 2022).
FAQ
What formula does the calculator use?
It subtracts birthdate from today, borrowing months or days when negative values appear, following Gregorian rules (ISO 8601:2004).
How are leap years handled?
The script adds 29 February in years divisible by 4, except 100 unless also by 400, mirroring astronomical practice (USNO, 2023).
What date range can I enter?
You can choose any date from 01-01-1970 to 31-12-275760 owing to JavaScript’s 64-bit time limits (ECMA-262, 2023).
How accurate is the total-days figure?
It counts every 24-hour block between midnight UTC values, producing exact day totals for all dates after 1970 (Mozilla Docs, 2024).
Can I get my zodiac sign without astrology knowledge?
Yes. The tool cross-references your month-day with twelve preset ranges and outputs the matching sign (Royal Astronomical Society, 2022).
How do I use the next-birthday countdown?
Plan parties or reminders: subtract today from your upcoming birthday; the script displays the remaining days automatically.
Is this age valid for legal documents?
Courts accept Gregorian-based calculations; verify the displayed age matches official records before submission (US Courts Manual, 2023).
What makes this method reliable?
“The Gregorian calendar repeats every 400 years, ensuring accuracy within one day,” notes the US Naval Observatory (USNO, 2023).
Important Disclaimer
The calculations, results, and content provided by our tools are not guaranteed to be accurate, complete, or reliable. Users are responsible for verifying and interpreting the results. Our content and tools may contain errors, biases, or inconsistencies. We reserve the right to save inputs and outputs from our tools for the purposes of error debugging, bias identification, and performance improvement. External companies providing AI models used in our tools may also save and process data in accordance with their own policies. By using our tools, you consent to this data collection and processing. We reserve the right to limit the usage of our tools based on current usability factors. By using our tools, you acknowledge that you have read, understood, and agreed to this disclaimer. You accept the inherent risks and limitations associated with the use of our tools and services.
