US pregnancy reference
US Pregnancy Due Date Calculator
Estimate a due date from the first day of the last menstrual period. A pregnancy care professional may revise the official date.
Estimated due date
Calculating40-week estimate from LMP.Calculation Basis and Official Sources
Uses the common 280-day or 40-week estimate from the first day of the last menstrual period.
Official rules change often. Before filing, borrowing, signing, paying or relying on a result, verify the latest source from the IRS, SSA, state or local agency, lender, employer or qualified professional.
This calculator gives a rough pregnancy dating estimate only. It is not medical advice, diagnosis, treatment, prenatal care guidance, emergency guidance, legal advice, insurance advice or any other professional advice.
Actual dating can change after ultrasound, ovulation timing, cycle irregularity, IVF dating, multiple pregnancy, miscarriage history, medical risk factors or clinician review. Use the due date and pregnancy week provided by your OB-GYN, midwife or licensed medical professional as the official reference.
Calcitda does not guarantee accuracy, completeness, timeliness or fitness for your situation. To the fullest extent permitted by law, Calcitda and its operator are not responsible for losses, injuries, claims or decisions arising from use of, or reliance on, this calculator. Nothing here limits liability that cannot legally be limited.