How Many Days Until My Next Birthday — and How Old Will I Be?.

Your next birthday is the next annual occurrence of your date of birth. To work out how many days away it is, compare today’s date with that date in the current year; if it has already passed, use next year instead.

The age you will reach is usually simple: subtract your birth year from the birthday year. But people often want more detail—the exact years, months and days since birth—rather than just a whole number.

Why can it be confusing?

Dates near the end of a month, different month lengths and leap years can make mental arithmetic unreliable. Leap-day birthdays are the clearest example: 29 February only occurs in leap years, so some people celebrate on 28 February or 1 March in other years depending on personal preference and local context.

Get the exact answer

The Age Calculator lets you enter your date of birth and shows your age in years, months, days and hours, along with the number of days until your next birthday.

This is useful for more than just birthday curiosity: forms, milestone planning, countdowns and checking an exact age at a particular point all benefit from a proper date calculation rather than a rough estimate.

<div class=“author-bio”> <strong>About the author:</strong> Richard Shaw, 30+ yrs software eng. 20 yrs automotive software, globally used retention solutions. Prolific SaaS dev, runs Rezero Software with his family. Contact: rich@rezero.net | rezero.net | @RichShawX </div>