Tools Categories Recommended Diagnostic tests

translate expand_more

Pregnancy Due Date Calculator

Choose the dating method you know best and see the estimated due date, current pregnancy week, trimester, and full-term reference window.

Health Waiting for result

Was this tool helpful?

Report issue

Result for the reference date

Feb 12, 2027

Estimated due date

Current stage

First trimester

Gestational age today

12wk 0days

Days to due date

196 days

Pregnancy day

85 / 280 days

Progress toward 280 days

30%

Reference birth window

Jan 22, 2027 - Feb 26, 2027

37 weeks through 42 weeks

Choose a dating method

Use the most reliable information you have for a steadier estimate.

Inputs for this method

Reference date

First day of last periodAverage cycle length

Pregnancy timeline

Dates are calculated in your browser and are not saved to the server.

12wk 0days

12wk

20wk

28wk

37wk

40wk

42wk

Helpful week markers

12wk

Early check-in

Jul 31, 2026

20wk

Mid-pregnancy scan window

Sep 25, 2026

28wk

Third trimester begins

Nov 20, 2026

37wk

Full term begins

Jan 22, 2027

40wk

Due date

Feb 12, 2027

42wk

Needs follow-up

Feb 26, 2027

Review notes

check_circleLMP dating adds 40 weeks, or 280 days, to the first day of the last menstrual period.
check_circleConception or ovulation dating adds about 266 days.
check_circleIf ultrasound or clinical dating changed your due date, follow your clinician date first.

Medical reference notice

This calculator is an educational estimate and does not replace medical care. Follow your obstetric clinician for pain, bleeding, high-risk pregnancy, IVF dating, or ultrasound redating.

Health use notice

This tool is for general reference only and does not replace medical, nutrition, diagnostic, or treatment advice. For health decisions, confirm the result with a clinician, registered specialist, or official guidance.

Result workspace

Save this result, compare previous runs, or share a report.

Calculation methods

LMP: last period start + 280 days + cycle difference
Conception: conception date + 266 days
IVF: transfer date + 266 days - embryo age
Ultrasound: work backward from gestational age on scan day

How it works

Due dates are commonly estimated around 40 weeks of pregnancy, but actual birth dates vary. This tool calculates the date from your chosen method and shows today gestational age plus the full-term reference window.

Usage notes

LMP method: LMP + 280 days, adjusted if the cycle is not 28 days.
Conception method: conception date + 266 days.
Ultrasound method: subtract the scan gestational age, then add 280 days from the estimated pregnancy start.