Pregnancy Calculator - Due Date & Trimester Milestones
Free online pregnancy calculator. Estimate your baby due date, current gestational age, and trimester milestones using Naegele’s rule.
Inputs
🔒 Local Processing| Trimester Milestone | Gestational Span | Status |
|---|---|---|
| First Trimester | Weeks 1 to 12 | Completed |
| Second Trimester | Weeks 13 to 27 | Completed |
| Third Trimester | Weeks 28 to 40 | In Progress |
How to Use This Calculator
- Select the first day of your last menstrual period and average menstrual cycle length.
Formula & Mathematical Method
Naegele’s clinical rule adjusted for menstrual cycle length.
EDD = LMP + 280 days + (Cycle Length - 28 days)Explanation of Variables
| Symbol | Variable Name | Description & Role in Calculation |
|---|---|---|
| LMP | Last Menstrual Period | First date of the last normal period. |
Worked Calculation Examples
LMP March 1, 2026
Scenario: 28-day cycle.
Interpretation of Results
Health and metabolic metrics are calculated using validated empirical equations (such as Mifflin-St Jeor, Devine, or Boer formulations). Results provide statistical estimates of physiological parameters for general wellness planning.
Estimated Physiological Value
Your calculated metabolic or anthropometric metric based on standard demographic averages.
Key Context: Use this figure as an informational baseline for nutritional or fitness goal setting.
Practical Use Cases
Nutritional and Fitness Program Design
Establish structured dietary intake targets, hydration goals, or training heart rate zones.
Long-Term Wellness Progress Tracking
Monitor changes in body composition, cardiovascular recovery, or metabolic requirements over time.
Limitations & Key Assumptions
- Formulas are derived from population-level clinical studies and cannot account for unique genetic, endocrine, or pharmacological differences.
- Hydration, body fat, and calorie needs fluctuate with daily temperature, humidity, stress, and hormonal cycles.
- Calculations are informational estimates and are NOT medical diagnoses, clinical evaluations, or therapeutic advice. Consult a qualified healthcare professional.