Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Pregnancy
Due Date Calculator
Estimates your baby's due date by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP) using Naegele's Rule. Use it in early pregnancy to plan prenatal appointments, milestones, and parental leave.
Fill in the required fields to see your result.
Pregnancy
Due Date Calculator
Estimates how many days remain until your due date and your current pregnancy week from how many days ago your last period (or conception/ultrasound reference) was, plus cycle length and any ultrasound adjustment.
Fill in the required fields to see your result.
Key differences
| Due Date Calculator | Due Date Calculator | |
|---|---|---|
| Category | Pregnancy | Pregnancy |
| Inputs required | 1 | 4 |
| Result | Days until due date (days) | Due Date Countdown |
| What it does | Estimates your baby's due date by adding 280 days (40 weeks) to the first day of your last menstrual period (LMP) using Naegele's Rule. Use it in early pregnancy to plan prenatal appointments, milestones, and parental leave. | Estimates how many days remain until your due date and your current pregnancy week from how many days ago your last period (or conception/ultrasound reference) was, plus cycle length and any ultrasound adjustment. |