INTERACTIVE CALCULATOR
Pregnancy weeks
Estimate gestational age and a due date from your last period.
UNDERSTAND YOUR NUMBERS
How to read your result
A worked example
Seventy days after the first day of your last period corresponds to ten completed weeks. A due date is an estimate, not an exact appointment.
How it is calculated
Gestational age starts from the last period. The due-date estimate adds 280 days and adjusts the usual cycle length relative to 28 days.
Common mistakes and limitations
If the date is uncertain or your cycles are irregular, speak to your healthcare professional. Ultrasound dating may be more accurate. These inputs are not saved, shared or exported.
Content by Numelva · Methods, sources and limitations ↗