Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

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.

Days Since Last Period (or chosen reference) (days)

Average Cycle Length (days)

Calculation Method

Ultrasound Adjustment (days)

Fill in the required fields to see your result.

Pregnancy

Due Date Calculator

Calculates how many days remain until your estimated due date from how many days ago your last period (or conception) occurred, adjusting for cycle length or luteal phase.

Calculation Method

Days Since Last Period / Conception (days)

Average Cycle Length (days)

Luteal Phase Length (days)

Fill in the required fields to see your result.

Key differences

	Due Date Calculator	Due Date Calculator
Category	Pregnancy	Pregnancy
Inputs required	4	4
Result	Due Date Countdown	Due Date Countdown
What it does	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.	Calculates how many days remain until your estimated due date from how many days ago your last period (or conception) occurred, adjusting for cycle length or luteal phase.