Birthday Calculator — Next Birthday Date & Countdown

Use this free online birthday calculator to find your next birthday, how many days are left until your birthday, which weekday it will fall on, and the age you will turn on that date.

Just enter your date of birth and optionally the date you want to count from. The tool gives you a simple birthday countdown, perfect for planning parties, trips and surprises.

Birthday inputs
Date of birth (required)

Enter your full date of birth with a four-digit year so the birthday calculator can show your correct age.

Count from date (optional)

Leave these fields empty to count from today, or set a custom date (for example a move date, exam date or the start of your holiday).

The birthday calculator works with calendar dates only — no time zones, no hours, just clear days and years.
Birthday results

Next birthday date

—
Your upcoming birthday on the calendar.

Days until birthday

—
How many days are left from the chosen date.

Age on next birthday

—
The age you will turn on that birthday.

Birthday weekday

—
Day of the week of your next birthday.

Enter your date of birth above and optionally a “count from” date to see your next birthday and days left.

Free birthday calculator: find your next birthday in seconds

This online birthday calculator shows you the exact date of your next birthday, how many days are left until your birthday and the age you will be on that day. Instead of counting months on a wall calendar or guessing if your birthday falls on a weekend, you can let the calculator do everything automatically.

Many people search for long questions like “how many days are left until my birthday from today”, “what day of the week is my next birthday” or “how old will I be on my next birthday date”. This page is built exactly for those real searches: simple fields, clear birthday countdown and extra useful information on a single screen.

How the birthday calculator works behind the scenes

The logic is simple: the calculator takes your date of birth and compares it to a second date (usually today) to find the next birthday after that day. The steps look like this: 

1. Read your date of birth
   birth = (birthYear, birthMonth, birthDay)

2. Choose the "count from" date
   from = (year, month, day)
   If you leave it empty, the calculator uses today's date.

3. Build a birthday for the current year
   candidateBirthday = (from.year, birthMonth, birthDay)

4. If that birthday is already in the past:
   nextBirthday = (from.year + 1, birthMonth, birthDay)
   otherwise:
   nextBirthday = candidateBirthday

5. Find the difference in days
   daysUntil = nextBirthday − from

6. Work out how old you will be
   ageOnNextBirthday = nextBirthday.year − birthYear

Special cases like leap years are handled automatically by the browser calendar. If you are born on 29 February, the birthday calculator will adjust the next birthday to a nearby date in non-leap years so you always get a usable countdown.

Why use a birthday calculator instead of doing it in your head?

At first, counting days to your birthday sounds easy. But it quickly becomes confusing when you try to remember how many days each month has, what happens around leap years and how to handle year changes. The birthday calculator avoids all of that and gives you instant, accurate results.

Common reasons people use a birthday countdown tool include:

  • Planning a birthday party or event date and sending invitations.
  • Checking if your birthday falls on a weekend or weekday.
  • Preparing travel plans or surprise trips around someone’s birthday.
  • Seeing how many days are left until a child’s first birthday or a special milestone.
  • Creating a personal birthday countdown for social media or a website.

Instead of guessing, this calculator acts as a small personal assistant for birthday dates and countdowns, using the real calendar of your device.

How to use the birthday calculator step by step

1. Enter your date of birth

In the first line of the form, type your birth day, month and year. Always use a four-digit year such as 1990 or 2005.

2. Choose the date you want to count from (optional)

In the second line, you can set a custom “count from” date. If you leave all three fields empty, the calculator automatically uses today. This is the most common usage for people who simply want to know how many days are left until their birthday from now.

A custom count from date is useful if you want to know your birthday countdown from a future moment, such as the start of a trip, the first day of school, or the beginning of a new job.

3. Click “Calculate birthday”

After you press the green button, the birthday calculator shows:

  • The exact date of your next birthday.
  • The number of days left until that date.
  • The weekday (Monday, Tuesday, etc.) of the next birthday.
  • The age you will be on your next birthday.

The page scrolls gently to the results card so you can see your birthday countdown without manually searching for it.

Examples: how many days until my birthday?

Example 1 — Simple birthday countdown from today

Date of birth: 10 / 08 / 2000

Count from: today

Suppose today is 16 / 11 / 2025. The birthday calculator will:

  • Find the next birthday on 10 / 08 / 2026.
  • Count how many days are left between 16 / 11 / 2025 and that date.
  • Show the weekday of 10 / 08 / 2026.
  • Tell you that you will turn 26 years old on that day.

Example 2 — Birthday countdown from a future date

Imagine you are planning a long trip and you want to know how many days are left from the start of the trip until your birthday.

Enter your date of birth at the top, then use the trip start date as the “count from” date. The tool behaves like a birthday calculator from specific date, not just from today.

Example 3 — Checking children’s birthdays

Parents often want to know exactly how many days are left until a child’s birthday so they can book venues, order cakes and prepare gifts. Enter the child’s date of birth and the current date, and the calculator will display a clean countdown in days.

What the birthday calculator results really mean

The birthday calculator gives several different pieces of information. Here is what each one means:

  • Next birthday date — the next calendar date when your day and month of birth occur after the “count from” date. This might be later in the same year or in the next year.
  • Days until birthday — the number of full calendar days between the “count from” date and your next birthday date. If the result is zero, it means today is your birthday.
  • Age on next birthday — how old you will be on the upcoming birthday, calculated from your birth year.
  • Birthday weekday — the day of the week (Monday, Tuesday, etc.) your next birthday will fall on, useful for planning events.

Popular long-tail birthday calculator searches this page can answer

With just one small form, this birthday calculator can answer many specific questions such as:

  • “how many days are left until my next birthday from today online”
  • “on which day of the week is my birthday this year”
  • “birthday calculator to know how old I will be on my birthday”
  • “countdown to my birthday date without time zones”
  • “next birthday date and age calculator from date of birth”

Instead of visiting multiple websites, you can reuse this single tool for yourself, your family and your friends just by changing the date of birth fields.

Tips for using your birthday result

Plan events and bookings early

When you know the weekday and the number of days remaining, it becomes easier to decide when to book restaurants, party venues or travel tickets. Many people like to check if their birthday is on a Friday or Saturday before they choose a party date.

Combine the birthday calculator with age tools

You can use this page together with an age calculator or age on date tool. First calculate the next birthday and how old you will be, then confirm your exact age today or on any other date.

Make personal challenges and milestones

Knowing the number of days left until your birthday is great for setting personal challenges such as “exercise every day until my birthday” or “save a fixed amount of money before my next birthday”.

Frequently asked questions about the birthday calculator

Does the calculator work for leap year birthdays?

Yes. If you are born on 29 February, the browser calendar inside the tool deals with leap years correctly. In non-leap years the next birthday will shift to a nearby valid date so you still get a usable countdown.

What happens if the “count from” date is after my next birthday?

The birthday calculator always looks for the next birthday after the “count from” date. If the date you choose is already past your birthday for that year, the calculator jumps to your birthday in the following year.

Can I use this birthday calculator for someone else?

Absolutely. Just enter the other person’s date of birth and the date you want to count from. The tool does not store any data after you close or refresh the page, so it is easy to reuse and completely private.

Does the time of day or time zone matter?

No. This birthday calculator is based only on calendar dates. It does not use hours, minutes or time zones. That keeps the results simple and stable, and makes them perfect for planning events and reminding yourself how many days are left.

Will my date of birth be saved anywhere?

No sign-up or login is required. All calculations happen inside your browser. When you refresh or close the page, the values disappear, which makes this a convenient birthday calculator without registration.