How is a due date calculated?

The standard method (Naegele's Rule) adds 280 days (40 weeks) to the first day of your last menstrual period.

How accurate is the due date?

Only about 5% of babies are born on their exact due date. Most births happen within 2 weeks before or after the estimated date.

Most home pregnancy tests are accurate from the first day of a missed period. Testing a few days earlier may give a false negative.

根據最後一次月經（LMP）計算預產期、目前孕週和孕期。

文字輸入

根據最後一次月經（LMP）計算預產期、目前孕週和孕期。由 JustUse.me 提供 — 免費、無廣告、保護隱私。此工具完全在你的瀏覽器中運行，你的檔案不會被上傳至任何伺服器。