Measure consistently
Use the first day of the last normal menstrual period, not the final day of bleeding, and enter the date on which progress should be calculated.
Pregnancy dating and milestone worksheet
Turn an LMP date into a complete pregnancy timeline.
Estimate gestational age, due date, trimester, time remaining and major dating milestones from the first day of the last menstrual period, with an explicit cycle-length adjustment.
The calculation runs locally in this browser. Educational outputs do not replace professional assessment, diagnosis, treatment or emergency care.
Method and interpretation guide
Use the pregnancy timeline result as a transparent estimate
Use the first day of the last normal menstrual period, not the final day of bleeding, and enter the date on which progress should be calculated. The worksheet exposes its assumptions so the result can be checked instead of accepted as a black box.
Read the assumptions
Naegele-style LMP dating assumes ovulation timing that may not match an individual cycle. A clinician may establish or revise the official estimated due date using documented clinical criteria.
Escalate important decisions
A calculator cannot examine symptoms, medical history, medication effects or measurement quality. Use qualified professional guidance when the decision has health consequences.
Local calculation
Inputs are processed in this browser. No account or external calculator is required to produce the result.
False precision
Extra decimal places do not remove biological variation, input error or limits in the underlying population equation.
Scope
Naegele-style LMP dating assumes ovulation timing that may not match an individual cycle. A clinician may establish or revise the official estimated due date using documented clinical criteria.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.