About the Half Birthday Calculator
The date exactly six months from your birthday, and how far away it is.
Also known as: half birthday date, six months from birthday, when is my half birthday.
How to use this calculator
- Enter date of birth, today.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
half birthday = birthday + 6 months
Worked example
Using the values pre-filled in the calculator above:
- Date of birth: 1990-06-15
- Today: 2026-09-22
the calculator returns:
- Half birthday: Tuesday, December 15, 2026
- Days away: 84
- Day of the week: Tuesday
- You will be: 36 and a half