Half Birthday Calculator

Your half birthday is exactly six months from your birthday. Find the next one and start the countdown.

Your birthday

Name (optional)

What is a half birthday?
It’s the date exactly six months after (or before) your real birthday — for example May 15 → November 15.

If your birthday falls on the 29th–31st of a month, the half birthday rolls to the last day of the six-months-away month.

🎉 Exactly 6 months

Calculated from your real birthday.

📅 Rollover safe

Handles month-end birthdays correctly.

⏱ Countdown

Days until the next half birthday.

🔒 Private

All calculations run locally in your browser.