Period Calculator

Pregnancy Calculator
Estimate your due date and current gestational age based on the first day of your last menstrual period (LMP).

What this calculator does

This pregnancy calculator estimates your due date and current gestational age based on the first day of your last menstrual period (LMP). It assumes a typical 280-day (40-week) pregnancy.

Use it for a quick reference only. Actual due dates vary and are updated by healthcare providers who consider cycle length, ultrasound measurements, and other clinical information.

How to use this calculator

Enter your information in the fields above, run the calculation, and review the result to understand what it means for your situation.

How to interpret your result

Look at the output in the context of your overall goals rather than in isolation. Consider how sensitive the result is to changes in your inputs (for example, adjusting the amount, rate, or time) to understand which factors matter most.

Limitations and notes

This tool is a simplified model and does not capture every nuance of real life. Treat it as a planning aid, not a guarantee. For important financial or health decisions, combine these results with professional advice and more detailed analysis.