Compare calculators

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

Fetal Growth Calculator

Estimates fetal weight from ultrasound biometry measurements including abdominal circumference, biparietal diameter, and femur length. Useful for tracking fetal growth between ultrasound appointments.

Gestational Age (weeks)

Biparietal Diameter (BPD) (mm)

Abdominal Circumference (AC) (mm)

Femur Length (FL) (mm)

Fill in the required fields to see your result.

Pregnancy

Pregnancy Week Calculator

Tells you how many weeks pregnant you are from how many days have passed since your reference date (LMP, conception, or due date), with a cycle-length adjustment in days.

Date Type

Days Since Reference Date (days)

Cycle Length Adjustment (days)

Fill in the required fields to see your result.

Key differences

	Fetal Growth Calculator	Pregnancy Week Calculator
Category	Pregnancy	Pregnancy
Inputs required	4	3
Result	Estimated Fetal Weight (grams)	Current Pregnancy Week (weeks)
What it does	Estimates fetal weight from ultrasound biometry measurements including abdominal circumference, biparietal diameter, and femur length. Useful for tracking fetal growth between ultrasound appointments.	Tells you how many weeks pregnant you are from how many days have passed since your reference date (LMP, conception, or due date), with a cycle-length adjustment in days.