Pregnancy Progress Calculator

Enter Pregnancy Details

Use one dating method, add a reference date, and review estimated progress. This tool supports LMP, conception, due date, and ultrasound inputs.

Calculation Method

First Day of Last Period

Average Cycle Length (Days)

Conception Date

Estimated Due Date

Ultrasound Date

Gestational Weeks at Scan

Additional Days at Scan

Reference Date

Example Data Table

These examples show how different input methods can produce a pregnancy progress summary.

Method	Primary Input	Reference Date	Estimated Due Date	Gestational Age	Trimester
Last Menstrual Period	LMP: January 10, 2026 Cycle: 28 days	March 6, 2026	October 17, 2026	7 weeks 6 days	First Trimester
Conception Date	Conception: February 1, 2026	March 20, 2026	October 25, 2026	6 weeks 5 days	First Trimester
Ultrasound Dating	Scan: March 1, 2026 Age: 9 weeks 2 days	April 15, 2026	September 25, 2026	15 weeks 5 days	Second Trimester

Formula Used

Due Date from LMP: LMP + 280 days + (cycle length − 28 days)
Due Date from Conception: conception date + 266 days
LMP from Due Date: due date − 280 days
LMP from Ultrasound: scan date − entered gestational age in days
Gestational Age: reference date − estimated LMP date
Pregnancy Progress Percentage: (gestational age in days ÷ 280) × 100
Estimated Fetal Age: gestational age in days − 14 days
Trimester thresholds: first trimester < 14 weeks, second trimester 14–27 weeks, third trimester 28–40 weeks

How to Use This Calculator

Select the dating method that matches the information you already have.
Enter the related date fields. Add cycle length only for the LMP method.
Choose a reference date to see pregnancy progress on that day.
Click Calculate Progress to generate the summary above the form.
Review gestational age, trimester, due date, progress percentage, and milestone dates.
Use the export buttons to save your results as CSV or PDF.

Helpful Notes

Important: This calculator provides educational estimates. Clinical dating, ultrasound interpretation, and care decisions should always be confirmed by a qualified healthcare professional.

This tool is especially useful for comparing date methods, estimating trimester changes, and planning around upcoming checkpoints during pregnancy.

Frequently Asked Questions

1. What does this calculator show?

It estimates gestational age, due date, trimester, pregnancy week, progress percentage, milestone dates, and remaining days using the dating method you choose.

2. What is the difference between gestational age and fetal age?

Gestational age counts from the last menstrual period. Fetal age is usually about two weeks shorter because conception typically happens around two weeks after that date.

3. Which dating method should I use?

Use the method supported by your records. LMP is common, conception date can help with known timing, and ultrasound dating is often useful when cycles are uncertain.

4. Can I use an irregular cycle length?

Yes. The LMP method includes cycle length adjustment, which can slightly shift the estimated due date when your cycle is shorter or longer than 28 days.

5. Why can due dates change after a scan?

An ultrasound may suggest a different gestational age than menstrual dating. Care teams sometimes update the estimated due date when imaging offers stronger timing evidence.

6. Does every pregnancy last exactly 40 weeks?

No. Forty weeks is a standard estimate from the last menstrual period. Actual delivery can occur earlier or later for many normal pregnancies.

7. Can I enter a future reference date?

Yes. A future reference date helps estimate progress at an upcoming appointment, travel date, or milestone, as long as it is not earlier than the pregnancy start date.

8. Does this calculator replace medical advice?

No. It is a planning and education tool. Always confirm dating, symptoms, and healthcare decisions with your doctor, midwife, or qualified clinician.