Compare calculators

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

Ovulation & Fertility Calculator

Predicts how many days until ovulation and your fertile window from how many days ago your last period started, your cycle length and luteal phase — and can project a later cycle.

Days Since Last Period Started (days)

Average Cycle Length (days)

Luteal Phase Length (days)

Cycles to Predict

Fill in the required fields to see your result.

Pregnancy

Pregnancy Body Changes Calculator

Track how your waist measurement is expected to expand week by week during pregnancy. Helpful for planning maternity clothing and monitoring abdominal growth against typical patterns.

Pre-pregnancy Waist (cm)

Current Pregnancy Week (weeks)

Fill in the required fields to see your result.

Key differences

	Ovulation & Fertility Calculator	Pregnancy Body Changes Calculator
Category	Pregnancy	Pregnancy
Inputs required	4	2
Result	Ovulation Prediction	Expected waist measurement (cm)
What it does	Predicts how many days until ovulation and your fertile window from how many days ago your last period started, your cycle length and luteal phase — and can project a later cycle.	Track how your waist measurement is expected to expand week by week during pregnancy. Helpful for planning maternity clothing and monitoring abdominal growth against typical patterns.