What is a Pregnancy Calculator?

A Pregnancy Calculator evaluates physiological metrics to guide health, fitness, or nutrition plans.

How often should I recalculate?

Recalculate every 4 to 8 weeks to track meaningful body composition or health changes.

Athletes with high muscle mass may require body-fat specific formulas like Katch-McArdle.

Combine balanced nutrition, regular resistance training, adequate sleep, and hydration.

Yes, all calculations run 100% locally in your browser with zero data storage.

Always consult a certified medical professional before starting aggressive diets or training regimes.

Calculated using standard mathematical and industry formulas.

Free online Pregnancy Calculator calculator to monitor your health, fitness, and nutrition goals.

Select your calculation method: last menstrual period (LMP) or conception date.
Enter the date using the date picker.
Adjust your average menstrual cycle length (default is 28 days).
Read your estimated due date, current gestational age in weeks and days, current trimester, and countdown.

Naegele's Rule & Gestational Age Calculation

Due Date = LMP + 280 days + (Cycle Length − 28 days)

LMP = First day of last menstrual period. Standard gestational length is 280 days (40 weeks).

For an LMP of Jan 1 with a 28-day cycle: Due Date = Jan 1 + 280 days = Oct 8.

Full-term pregnancy lasts approximately 40 weeks (280 days) from the first day of the last menstrual period (Naegele's rule).
Only about 4% of babies are born on their exact estimated due date; most arrive within 2 weeks before or after.
Conception typically occurs roughly 14 days after the first day of your last period in a standard 28-day cycle.
The first trimester spans weeks 1–12, the second trimester weeks 13–26, and the third trimester weeks 27–40.

The projected date of birth based on standard 40-week gestational age calculations.

The age of the pregnancy measured in weeks and days from the start of the last menstrual period, not actual fetal age.

Identifies your current stage of pregnancy to guide prenatal care and developmental expectations.

What is a Pregnancy Calculator?: A Pregnancy Calculator evaluates physiological metrics to guide health, fitness, or nutrition plans.
How often should I recalculate?: Recalculate every 4 to 8 weeks to track meaningful body composition or health changes.
Is this calculation accurate for athletes?: Athletes with high muscle mass may require body-fat specific formulas like Katch-McArdle.
How can I improve my results?: Combine balanced nutrition, regular resistance training, adequate sleep, and hydration.
Are results confidential?: Yes, all calculations run 100% locally in your browser with zero data storage.
Should I consult a physician?: Always consult a certified medical professional before starting aggressive diets or training regimes.

Pregnancy Weight Gain Calculator — Track recommended weight gain during pregnancy based on pre-pregnancy BMI and week.
Ovulation Calculator: Fertile Window & Dates — Calculate your most fertile days, estimated ovulation date, and conception window based on your menstrual cycle length. Accurate fertility planning calendar.
BMI Calculator: Body Mass Index for Adults — Calculate your Body Mass Index (BMI) using metric or imperial units. Compare your score with official WHO weight categories from underweight to obese.

Note: JavaScript is required for live interactive calculations. Published formulas and reference content remain fully accessible above.