Enter Tracking Details
Example Data Table
| Example Input | Sample Value | Meaning |
|---|---|---|
| LMP Date | 2026-01-05 | Starting point for LMP dating. |
| Cycle Length | 30 days | Adjusts due date by 2 days. |
| Check Date | 2026-03-29 | Date used for weekly progress status. |
| Observed Weight | 300 g | Optional comparison against estimated weight. |
| Observed Length | 16.5 cm | Optional comparison against estimated length. |
| Next Appointment | 2026-04-10 | Helps create a scheduling reminder. |
Formula Used
1) LMP method: Due Date = LMP + 280 days + (Cycle Length − 28 days)
2) Conception method: Due Date = Conception Date + 266 days
3) Ultrasound method: Due Date = Ultrasound Date + (280 − Gestational Age at Scan)
4) Gestational Age: Gestational Age Days = 280 − Days Remaining Until Due Date
5) Progress: Pregnancy Progress % = (Gestational Age Days ÷ 280) × 100
6) Growth estimates: Estimated weight and length use interpolated reference points between known weekly milestones.
How to Use This Calculator
- Select the dating basis: LMP, conception, or ultrasound.
- Enter the matching date details for your chosen method.
- Add the check date to see progress for a specific day.
- Optionally enter observed weight and length from a report.
- Add the next appointment date to get a schedule note.
- Press Track Development to generate the summary.
- Review the result cards, graph, and variance values.
- Export the findings using the CSV or PDF buttons.
Frequently Asked Questions
1. What date method should I choose?
Use LMP if menstrual dates are known and cycles are predictable. Use conception date when timing is known clearly. Use ultrasound dating when a clinician advised that scan-based dating is more reliable.
2. Are the weight and length values exact?
No. They are educational estimates based on reference growth points and interpolation. Real measurements vary by scan method, fetal position, genetics, and clinical interpretation.
3. Why does cycle length affect due date?
A cycle longer or shorter than 28 days may shift ovulation timing. The calculator adjusts the standard LMP estimate to better reflect that difference.
4. What does progress percentage show?
It shows how much of the standard 280-day pregnancy timeline has passed. It is a planning indicator, not a measure of health or readiness for delivery.
5. Can I compare ultrasound measurements here?
Yes, you can enter observed weight and length values to compare them with the estimated reference numbers. Those comparisons are informational and should not replace clinical review.
6. Does this replace prenatal care?
No. This page is a tracking and planning tool only. Prenatal decisions should always be based on advice from your obstetrician, midwife, or qualified healthcare professional.
7. Why might my due date differ from another source?
Different tools may use different assumptions, rounding rules, or dating methods. Clinical providers may also revise dates after ultrasound findings and medical review.
8. What does the fruit-size comparison mean?
It offers a simple visual reference for weekly size changes. It is not a medical measurement and should be treated as a general educational comparison.