Birthday Calculator
Birthday calculator with age in years, the weekday you were born, days since birth and a countdown to your next birthday.
Enter a birthday to see the countdown and age details.
Last updated: August 2026
How this calculator is verified
Checked by True Calculator automated test suite on
- Formula verified against a published worked example in the automated test suite
- Edge cases (zero, negative, boundary and unit-mismatch inputs) covered by unit tests
The full verification method is on our how we verify page. Found an error? Tell us and we will re-check it.
When to Use This Calculator
Use the birthday calculator to get the complete story of any birthday in one screen — the weekday you were born on, your age in completed years, total days lived, and an exact countdown to the next birthday with its date and weekday. Families use it to plan celebrations and surprise parties, parents check admission-age details, and anyone curious about the day of the week of a birth can find it instantly. The adjustable on-date lets you compute stats as of any day, so you can see how old you will be at a future milestone or how the countdown looked last month. For leap-day birthdays, the automatic 1 March shift removes the annual confusion about when to celebrate, making this the go-to tool for precise birthday planning across India.
How to Use This Calculator
- Step 1: Enter the birthday, for example 20-03-1995, in the first date field.
- Step 2: Keep the on-date as today to see your current birthday stats, or change it to any date.
- Step 3: Read the age-last-birthday card to see completed years and the weekday you were born on.
- Step 4: Check the next-birthday cards for the exact countdown, the date, and the weekday it falls on.
Worked Example
Aarav was born on 20 March 1995. With the on-date set to 14 August 2026, the calculator shows he is 31 years old, was born on a Monday, and has lived 11,470 days. His next birthday is 20 March 2027 — 218 days away, a Saturday — when he turns 32. For a leap-day child born on 29 February 2004, the calculator shifts the celebration to 1 March 2027, 199 days after 14 August 2026, because 2027 is not a leap year.
Tips and Common Mistakes
- •Tip 1: Set the on-date to the birthday itself to confirm 'today' is the celebration day before sending wishes.
- •Tip 2: Use the born-weekday result for school records or keepsake projects that ask what day of the week you arrived.
- •Tip 3: For children, compare the days-since-birth figure a few days before the birthday to build the countdown excitement.
- ✗Mistake 1: Entering a birth date later than the on-date — the calculator rejects it since the birthday must come first.
- ✗Mistake 2: Expecting a 29 February birthday to appear every year; the calculator correctly moves it to 1 March in non-leap years.
Frequently Asked Questions
Which weekday was I born on?
Enter your birthday and the calculator shows the weekday of your birth — the day the calendar had on that date. For example, 20 March 1995 was a Monday. This is a popular detail for horoscopes, birth charts and school records, and the same result can be cross-checked with the day-of-week calculator on this site for any date.
How many days old am I today?
The calculator counts every full day from your date of birth to the chosen date. For a person born on 20 March 1995, the count to 14 August 2026 is 11,470 days. This total-day figure is used in medical dosing by age, insurance policy terms and curiosity — and it is the same number used by the chronological age calculator.
How is the next birthday date chosen?
The calculator looks for the next occurrence of your birth month and day after the chosen date. If that birthday falls in the same year it is used; otherwise the following year. For a 29 February birthday in a non-leap year, the celebration shifts to 1 March. The countdown shows the exact days remaining, such as 218 days to 20 March 2027.
Does this help with school admission age in India?
Yes. CBSE and state boards commonly require a minimum age — typically 5 or 6 years as of 31 March or 1 June of the admission year. Enter the child's birth date and the cutoff date to see the completed age in years, months and days, which is what schools ask parents to produce at admission time.
What if my birthday falls on a festival day?
The calculator works for any date, including festival days like Diwali or Holi that shift each year. Set the 'on date' to any date and it will show how many days remain to the next birthday and which weekday it falls on. Planning a party around a holiday date is a common use — the countdown makes the planning exact.
Compare these tools
- Age Calculator — Find your exact age in years, months and days from your date of birth
- Date Add Subtract Calculator — Add or subtract days, weeks, months or years to any date, including business days, and see the resulting weekday
- Date Difference Calculator — Count the exact days, weeks, months, years and business days between two dates, with hours and minutes too
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