Pregnancy Conception Calculator
💡 What Is a Pregnancy Conception Calculator?
The Pregnancy Conception Calculator helps you estimate when you conceived using your last menstrual period (LMP), ultrasound date, or estimated due date. Unlike due‑date tools, this calculator calculates backwards to highlight your fertile window and track pregnancy timelines more effectively choicespregnancy.org+9calculator.net+9micase.state.mi.us+9.

🧠 How It Works Pregnancy Conception Calculator
You can calculate your conception date by entering:
- LMP Date – Calculator estimates ovulation around 11–21 days after LMP calculator.net.
- Due Date (EDD) – Subtracts 266 days from your EDD to find the approximate conception.
- Ultrasound Scan Date – Uses biometry-based dating for reverse EDD and conception estimate nhs.uk+2perinatology.com+2flo.health+2.
Results include:
- Estimated conception date/range
- Primary fertile window
- Associated trimester and gestational age tracking
🗓️ Example Scenario
Option 1 – LMP
- LMP: May 1, 2025 → Estimated ovulation: May 14–17, 2025
Option 2 – EDD provided
- EDD: February 5, 2026 → Conception ≈ May 15, 2025 (EDD − 266 days)
Option 3 – Ultrasound date
- 12-week scan on July 1, 2025 → Adjusted conception ≈ April 15, 2025
📊 Conception Timeline Graph
mermaidCopyEditgantt
title Conception & Pregnancy Timeline
section Timeline
Ovulation Window :a1, 2025-05-10, 7d
Fertilization :after a1, 1d
First Trimester :after a1, 12w
Second Trimester :after a1+12w, 14w
Third Trimester :after a1+26w, 14w
This helps users visualize ovulation, conception, and trimester phases.
✅ Why Use This Calculator?
- 🎯 Clarify conception timing for personal or medical purposes
- 📅 Helps schedule early prenatal tests and appointments
- 🗓 Track progress by conception date rather than LMP
- 🔐 Fully private, free, and mobile-optimized
🔗 Internal Links
For added context and continuity:
🌐 Trusted External References
- Calculator.net – Pregnancy Conception Calculator — Provides conception date estimates based on LMP, EDD, or ultrasound en.wikipedia.org+12calculator.net+12micase.state.mi.us+12calculator.net+4americanpregnancy.org+4perinatology.com+4flo.healthamericanpregnancy.org+3perinatology.com+3nicheofficesolutions.co.uk+3calculator.net+1nicheofficesolutions.co.uk+1pampers.comflo.health+6tilburyhealthcentre.nhs.uk+6nicheofficesolutions.co.uk+6
- American Pregnancy Association – Calculating Conception — Explains how to calculate conception using LMP or ultrasound americanpregnancy.org+1americanpregnancy.org+1
These high-authority sources back up your tool’s logic and boost trustworthiness.
📝 Fertility & Conception Tips
- Expect some timing variation—fertile windows can range 2–7 days calculator.netflo.health.
- Accurate LMP or early ultrasound improves precision—scan around 10–14 weeks is most reliable americanpregnancy.org+15perinatology.com+15webmd.com+15.
- Tracking ovulation signs (temperature, cervical mucus) sharpens your conception date estimates.