Input Parameters
Gestational Timeline
Awaiting Inputs
Please enter the first day of your last menstrual period (LMP) and cycle length to estimate your gestational progress.
Estimate your pregnancy due date, track trimester progression, and view typical clinician discussion milestone windows.
Awaiting Inputs
Please enter the first day of your last menstrual period (LMP) and cycle length to estimate your gestational progress.
Your inputs are processed on this device. We do not store or transmit your health data.
This due date calculation is an estimate based on the first day of your last menstrual period. Actual dating may vary based on ultrasound measurements and clinical evaluation. Milestones are general educational estimates, not medical instructions.
This tool is for general educational use only and is not medical advice, diagnosis, or treatment. Talk to a qualified healthcare professional for personal medical guidance.
Cycle-Adjusted Due Date Calculation:
Due Date = LMP + 280 days + (Cycle Length - 28 days)Gestational Age Calculation:
Gestational Days = Today - LMP DateOur gestational library parses timestamps securely in local client-side memory, dividing total days by 7 to determine the pregnancy week index and using the remainder as gestational day count.
Standard pregnancy dating assumes a gestation period of 280 days (40 weeks) from the first day of your last menstrual period (LMP). Our calculator uses Naive Gestational Estimations, which adjusts this 280-day baseline to account for cycles that are shorter or longer than the standard 28-day model: Estimated Due Date = LMP Date + 280 days + (Your Cycle Length - 28 days)
Gestational age measures how far along a pregnancy is, counting from the first day of the last menstrual period rather than the date of conception. It is represented in completed weeks and days. Clinicians prefer this measurement because the date of your last period is usually easier to confirm than the precise date of ovulation or conception.
Only about 4% of babies are born precisely on their calculated due date. Due date estimators provide general guidelines. Ultrasound measurements during your first prenatal appointment represent the most accurate method for dating, and your OB/GYN or midwife will establish your official clinical timeline.