LMP Apr 1, 2026, 28 day cycle
- Gestational age today
- 4w 0d
- Estimated conception
- Apr 15, 2026
- Trimester
- First trimester
Pregnancy Calculator
Use this free pregnancy calculator to estimate due date, gestational age today, conception timing, and trimester from last period date.
Research-based formula Estimate limits shown Examples included Private history
Formula steps
- Start with the first day of the last menstrual period.
- Add 280 days, adjusting for cycle length compared with a 28-day cycle.
- Estimate conception near ovulation, about 14 days before the next period.
How to use the pregnancy calculator
- Enter the requested measurements, dates, lab values, or workout details.
- Check that the units and formula assumptions match what the tool is asking for.
- Press the calculate button to see the answer, supporting metrics, and formula steps.
- Read the estimate with the health disclaimer in mind, then copy the result if you need it for notes.
Common uses
Estimate an expected due date from LMP.
Check gestational age today.
Estimate conception timing from cycle length.
Use a simple date reference before clinical dating is confirmed.
Examples
Estimated due date
Due date adjusted later
Due date adjusted earlier
Frequently asked questions
Quick answers about formulas, inputs, estimate limits, professional guidance, examples, and private in-browser history.
What can I use the Pregnancy Calculator for?
Use it for quick educational estimates, planning, comparison, and trend checks. Health and fitness results should be interpreted with context, not as a diagnosis.
How does the Pregnancy Calculator calculate the result?
The calculator starts with the first day of the last menstrual period, adds about 280 days, and adjusts for cycle length.
Is this medical advice?
No. This page provides an educational estimate only. Talk with a qualified health professional before making medical, pregnancy, nutrition, medication, or safety decisions.
Are my health inputs private?
Yes. The calculator runs in your browser tab. Recent answers stay only on the page while you use it and are not sent to a server.