Classic tool
Pregnancy Weeks Calculator and Due Date Estimator
Estimate pregnancy weeks, due date, current trimester and approximate month from the last menstrual period.
Use this pregnancy weeks calculator to estimate gestational age, current trimester and due date based on the first day of the last menstrual period. It gives you a quick way to follow the pregnancy in weeks and days, compare appointment timelines and get an initial view of the overall schedule.
Beyond the estimated due date, the tool also shows an estimated conception date, the approximate pregnancy month and how many days remain until the projected date. You can adjust the average cycle length when your cycle is shorter or longer than the typical 28 days.
The result is meant as an informational reference and should not replace medical evaluation. If you need confirmation about gestational age, ultrasound dating, preterm birth risk or cycle differences, review the estimate with your healthcare professional.
Use clear inputs to get a more useful result.
How to use Pregnancy Weeks Calculator and Due Date Estimator
Open the tool, fill in the fields with the data you already have and generate the result step by step. If you want to compare scenarios, change one field at a time so it is easier to understand the impact of each value.
When Pregnancy Weeks Calculator and Due Date Estimator is useful
The goal here is simple: Estimate pregnancy weeks, due date, current trimester and approximate month from the last menstrual period. It works well for quick checks, planning, study and review before you move to a final decision or document.
What to review before using the result
Check units, labels, numbers, timing and any context that can change the meaning of the output. If the result will be used in a quote, technical task, published page or report, finish with a manual review.
Frequently asked questions
What should I prepare before using the tool?
Keep the key values, labels and units ready before filling in the fields. Cleaner inputs make the final result easier to review and compare.
Can I test different scenarios on the same page?
Yes. The safest approach is to change one field at a time, compare the outputs and note which value actually changes the final answer.
Is the result ready to use without checking it?
It is better to treat it as support. Review the output once more before using it in a quote, document, spreadsheet, technical task or published page.