Pregnancy Week Calculator

Calculate pregnancy weeks and days on a chosen date using your period, conception or due date. Includes cycle adjustment, due date and milestones. Data stays local.

Choose a calculation methodUse the most reliable date available to you.

Calculation method

First day of last period

Average cycle length

days

Used to adjust the estimate when your cycle is longer or shorter than 28 days.

As-of date

All dates are Gregorian. Calculations run in your browser without sending your data.

An informational estimateClinical dating can differ, especially after an early ultrasound. Follow the date and care plan confirmed by your healthcare professional.

Health reference ↗

ACOG ↗

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