Classic tool
Pregnancy Calculator
Calculate gestational age, trimester, approximate month and due date from the last menstrual period.
Use this pregnancy calculator to estimate gestational age from the first day of the last menstrual period, with an optional cycle-length adjustment. It helps you see how many weeks and days pregnant you are, which trimester applies and what estimated due date the standard calculation gives.
The tool also shows an estimated conception date, approximate pregnancy month and how many days remain until the due date based on the reference date you choose. It is informational only and does not replace prenatal care or an ultrasound assessment.
Use clear inputs to get a more useful result.
How to use Pregnancy Calculator
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 Calculator is useful
The goal here is simple: Calculate gestational age, trimester, approximate month and due date 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.