Pregnancy & Fertility
Body composition, nutrition, pregnancy and heart-health calculators based on WHO, NHS, ACOG and ACSM reference standards.
Gestational Age Calculator
Find out how many weeks pregnant you are from your last period or due date. Shows trimester, estimated due date and days remaining, per ACOG dating.
Pregnancy Due Date Calculator
Estimate your pregnancy due date from your last menstrual period, conception date, or IVF transfer using ACOG Naegele's Rule and ASRM conventions. Free tool.
Ovulation Calculator
Find your ovulation date and six-day fertile window from your last period and cycle length. Based on Wilcox et al. NEJM 1995. Free, private, no sign-up.
Fertility Window Calculator
Calculate your broadest possible fertile window from a range of cycle lengths. Designed for irregular cycles using earliest and latest ovulation estimates.
Conception Date Calculator
Estimate when conception likely occurred from your due date or birth date. Uses the 266-day (EDD minus 266) reverse formula with a ±3-day window.