Health & Fitness calculator
Pregnancy Due Date Calculator
Estimate your due date based on your last menstrual period.
About the pregnancy due date calculator
The pregnancy due date calculator estimates your due date using Naegele's rule based on your last menstrual period.
How to use this calculator
- 1
Enter last period date
Select the first day of your last menstrual period.
- 2
Enter cycle length
Enter your average cycle length (28 days by default).
- 3
View results
See your estimated due date and current week of pregnancy.
How the calculation works
Naegele's rule: Due date = LMP + 280 days (adjusted for cycle length). Conception typically occurs ~14 days after LMP.
Example: LMP Jan 1, 28-day cycle: Due date ≈ Oct 8.
Important health disclaimers
These calculators provide estimates based on population averages. Individual results vary based on genetics, body composition, medical conditions, and medications. Always consult a healthcare provider before starting a new diet or exercise program, especially if you have underlying health conditions.
Understanding body composition metrics
BMI doesn't distinguish muscle from fat. Body fat % is more accurate but depends on measurement technique. TDEE varies day-to-day based on activity. Macro targets are starting points — adjust based on your results, energy levels, and goals. Hydration needs increase with exercise, heat, and altitude.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about pregnancy due date calculator
How accurate is the pregnancy due date calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.