Pregnancy Due Date Calculator
Enter your last menstrual period or conception date to automatically calculate your due date, current gestational week, and days remaining. Free online tool - all data stays on your device, no server upload.
Medically, the due date is calculated from the first day of your last menstrual period (LMP): add 9 months (or subtract 3) and add 7 days. For example, if LMP is May 1, 2025, the due date would be February 8, 2026. Actual delivery may occur 1-2 weeks before or after, which is normal.
The due date is only an estimate. About 5% of pregnancies deliver on the exact due date, and 85% deliver within 1-2 weeks before or after. Actual dates are influenced by menstrual cycle, ovulation timing, and individual differences. Please follow your doctor's advice.
Count from the first day of your last menstrual period. Every 7 days equals 1 gestational week, with 40 weeks (280 days) being a full term pregnancy. For example, if it's 20 weeks and 3 days from your LMP, write it as 20w+3d. Gestational week is an important reference for assessing fetal development.