Pregnancy Due Date Calculator

Estimate your pregnancy due date from the first day of your last menstrual period (LMP). You can also adjust the calculation for your usual menstrual cycle length.

Select the first day of your last menstrual period, not the last day.
The standard calculation assumes a 28-day cycle. Enter your usual cycle length if known.

Please enter valid information.

Pregnancy Date Estimate

Estimated Due Date -
LMP Date -
Cycle Length -
Estimated Conception -

Estimated Pregnancy Milestones

These dates are calculated from the same LMP-based pregnancy timeline and are approximate.

12 Weeks -
20 Weeks -
28 Weeks -
37 Weeks -
40 Weeks -
Standard pregnancy dating is approximately: 40 weeks (280 days) from LMP

How is the due date calculated?

Pregnancy is conventionally dated from the first day of the last menstrual period, even though conception usually occurs later.

Standard Estimated Due Date = LMP + 280 days

A 28-day menstrual cycle is normally assumed. If your usual cycle is longer or shorter, this calculator adjusts the estimate by the difference.

Adjusted Due Date = LMP + 280 days + (Cycle Length - 28 days)

For example, a 30-day cycle adds:

30 - 28 = 2 days

Adjusted Due Date = Standard Due Date + 2 days
Important: This calculator provides an estimate only. The actual date of conception and delivery can differ from an LMP-based estimate, especially when cycles are irregular or the LMP is uncertain. Clinical pregnancy dating, including ultrasound when appropriate, may revise the estimated due date. Use the due date provided by your maternity healthcare professional for medical decisions and care planning.
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Pregnancy Due Date Calculator

Vedicaly's Pregnancy Due Date Calculator helps estimate an expected delivery date based on the information entered into the calculator. A due date is an estimate and does not predict the exact day a baby will be born.

How to Use the Pregnancy Due Date Calculator

Enter the requested date information into the calculator. The tool will use the entered date to estimate your expected due date and pregnancy timeline.

How Is a Pregnancy Due Date Estimated?

A common method estimates the due date as approximately 40 weeks, or 280 days, from the first day of the last menstrual period (LMP). This calculation assumes a typical menstrual cycle, so the estimate may vary when cycle length or ovulation timing differs.

How Long Is a Typical Pregnancy?

Pregnancy dating is generally measured from the first day of the last menstrual period. The estimated due date is around 40 weeks from that date, although actual delivery can occur before or after the estimated date.

Is the calculated due date exact?

No. A calculated due date is an estimate. The actual delivery date can differ from the estimated due date.

Can an ultrasound change the estimated due date?

Healthcare professionals may use ultrasound measurements, particularly from early pregnancy, when assessing pregnancy dating. Your healthcare professional can determine which dating information is most appropriate for your pregnancy.

Should this calculator replace medical advice?

No. This calculator is intended for general informational purposes and should not replace pregnancy dating, assessment or advice from a qualified healthcare professional.