CalculationTime

Pregnancy Due Date Calculator

Due date, gestational age and trimester context from one date.

Live math canvas

Your numbers, formula and explanation together

Pregnancy Due Date Calculator: 2027-03-08. 2 weeks 5 days as of 2026-06-20 · first trimester estimate · cycle adjustment +0 days.

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

LMP method: due date = LMP date + 280 days + (cycle length − 28 days). Conception method: conception date + 266 days. IVF method: transfer date + (266 − embryo day) days. Ultrasound method: scan date + (280 − reported gestational age in days).
  1. Apply the formulaLMP method: due date = LMP date + 280 days + (cycle length − 28 days). Conception method: conception date + 266 days. IVF method: transfer date + (266 − embryo day) days. Ultrasound method: scan date + (280 − reported gestational age in days).2027-03-082 weeks 5 days as of 2026-06-20 · first trimester estimate · cycle adjustment +0 days.

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

LMP year
2,026
LMP month
6
LMP day
1
As-of year
2,026
As-of month
6
As-of day
20
Cycle length
28 days

Resulting answer

2027-03-08

2 weeks 5 days as of 2026-06-20 · first trimester estimate · cycle adjustment +0 days.

Answer
2027-03-08
Live support
2 weeks 5 days as of 2026-06-20 · first trimester estimate · cycle adjustment +0 days.

Assumptions used

What this answer assumes

Estimate only; confirm pregnancy dating with a qualified health professional.

  • This is a conventional estimate only.
  • Ultrasound dating and clinical advice can change the estimated due date.
  • Dates are handled as UTC calendar days to avoid timezone drift.

Master’s Tip

How to use the result well

Master’s Tip: treat the due date as an estimate window, not a guaranteed delivery day.

Printable record

What belongs in the saved calculation

Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.

LMP year
2,026
LMP month
6
LMP day
1
As-of year
2,026

Embeddable calculator

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Explain it like I'm 12

The due date calculator estimates an expected due date and current gestational age from the dating method the user actually has.

Formula

LMP method: due date = LMP date + 280 days + (cycle length − 28 days). Conception method: conception date + 266 days. IVF method: transfer date + (266 − embryo day) days. Ultrasound method: scan date + (280 − reported gestational age in days).

Worked example

For an LMP date of 2026-06-01 and 28-day cycle, the estimated due date is 2027-03-08.

Professional note

Master’s Tip: treat the due date as an estimate window, not a guaranteed delivery day.

Regional and unit assumptions

Common 280-day LMP method. Clinical pregnancy dating should be confirmed with a qualified health professional.

Assumptions and limitations

Methodology & Accuracy

How this calculator is checked

CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.

Formula used

LMP method: due date = LMP date + 280 days + (cycle length − 28 days). Conception method: conception date + 266 days. IVF method: transfer date + (266 − embryo day) days. Ultrasound method: scan date + (280 − reported gestational age in days).

Standard or basis

Common 280-day LMP method. Clinical pregnancy dating should be confirmed with a qualified health professional.

Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.

Master's Tip

Master’s Tip: treat the due date as an estimate window, not a guaranteed delivery day.

Questions

Why add 280 days?

The common LMP convention estimates pregnancy at about 40 weeks from the first day of the last menstrual period.

Can ultrasound change the date?

Yes. Clinicians may revise the estimated due date based on ultrasound and medical history.