Due Date Calculator
Use a clinician date, last period and cycle length, ovulation, an ultrasound report, or IVF timing. Enter one source or compare several.
Estimate my due datePregnancy Calculators
Research-based pregnancy tools
Estimate a due date, conception timing, or exact pregnancy weeks and days. Start with one source of dating information or compare as many as you have.
Choose a calculator
Conception Calculator
Estimate fertilization timing and, when applicable, the days intercourse could have led to pregnancy.
Estimate conception timingPregnancy Week Calculator
See completed weeks and additional days today or on another date, including the current and next week boundaries.
Calculate weeks and daysWhich calculator should I use?
- I want to know when the baby is due
- Use the Due Date Calculator.
- I want to know when conception may have happened
- Use the Conception Calculator.
- I want to know how many weeks pregnant I am
- Use the Pregnancy Week Calculator.
- I already know my due date and want labor probabilities
- Use the separate Labor Probability Calculator.
One consistent timeline
Save once and reuse your dates
After calculating, you can choose to save the pregnancy timeline in this browser. The due date, conception, and pregnancy week tools can then reproduce results from the same dating source instead of asking you to start over.
Have more than one source?
Enter all the information you have. The calculators rank clinician-established dates, IVF timing, ultrasound reports, menstrual dates, and ovulation estimates by dating usefulness. They compare the results without averaging due dates.
Built around published pregnancy-dating guidance
The tools use conventional pregnancy-dating formulas and explain the source selected for each result. Their methodology cites professional guidance and peer-reviewed research on ultrasound dating, natural pregnancy-length variation, and the fertile interval.