Enter your period date, due date, or ultrasound details to instantly see your current trimester and pregnancy stage.
How This Calculator Works
This tool functions as a simple and clear pregnancy trimester calculator, helping you understand exactly where you are in your pregnancy journey. Whether you know your Last Menstrual Period, your Estimated Due Date, or you have ultrasound measurements, the calculator translates that information into:
- Your current gestational week and day
- The trimester you’re in
- Your estimated due date
- A quick progress percentage
- A helpful trimester breakdown table
Everything is based on the standard 40-week model used in clinical settings.
Example Calculation
Estimate Based On:
Last Menstrual Period (LMP)
- First Day of Last Period: 01/11/2025
- Average Cycle Length: 28 days
Result Summary
| Category | Value |
|---|---|
| Current Gestational Age | 2 weeks 3 days |
| Current Trimester | 1st Trimester |
| Estimated Due Date | Sat Aug 08 2026 |
| Progress | 6% |
Trimester Overview
| Trimester | Weeks | Period (Start–End) |
|---|---|---|
| 1st Trimester | 0–13 | Sat Nov 01 2025 to Sat Jan 31 2026 |
| 2nd Trimester | 14–27 | Sat Feb 07 2026 to Sat May 09 2026 |
| 3rd Trimester | 28–40 | Sat May 16 2026 to Sat Aug 08 2026 |
These ranges reflect the common medical timeline used to track how pregnancy progresses from early development to full term.
Why This Trimester Tool Is Helpful
Pregnancy is often talked about in weeks, but many people prefer knowing which trimester they are currently in. This calculator gives both views so you can easily understand your stage, plan appointments, follow weekly guides, and monitor your progress with confidence.