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Calculator Collection

Due Date Calculator vs Gestational Age Calculator

Two calculators for the same neighbourhood of questions. Here is what each measures, what you feed in, and where you'd reach for one over the other.

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.

Answers
Days until due date (days)
Inputs
Last Menstrual Period
Pregnancy

Gestational Age Calculator

Converts the number of days since your last menstrual period into gestational age expressed as weeks and days. Use it at any point in pregnancy to know your exact stage for prenatal care, screenings, and milestone tracking.

Answers
Gestational age (weeks)
Inputs
Days since Last Menstrual Period

At a glance

Due Date CalculatorGestational Age Calculator
CategoryPregnancyPregnancy
AnswersDays until due dateGestational age
Inputs11
Result unitdaysweeks

When to use each

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.

Converts the number of days since your last menstrual period into gestational age expressed as weeks and days. Use it at any point in pregnancy to know your exact stage for prenatal care, screenings, and milestone tracking.

Compare page seeded from editorial siblings — both calculators list each other as related.