Conception Date Estimator

Conception Date Estimator – Find Out When You Conceived

Trying to figure out when your baby was conceived? Our free Conception Date Estimator helps you estimate your conception date quickly and privately — no signups, no personal data required.

What Is a Conception Date Estimator?

This tool helps you estimate the likely day you conceived based on:

• The first day of your last menstrual period (LMP), or
• Your baby’s due date (if already known)

It uses the average time of ovulation — about 14 days after your period starts — to calculate the most probable conception date.

How to Use the Tool

You have two options:

🔹 Option 1: If you know your due date
→ Enter your due date, click Estimate, and we’ll tell you your likely conception day.

🔹 Option 2: If you know the first day of your last period
→ Enter that date, and we’ll estimate your conception day based on a standard 28-day cycle.

You’ll also see:

• How far along you are today
• The day fertilization likely occurred
• Estimated window of intercourse

Why This Matters

• Helps you pinpoint when conception likely happened
• Gives a better understanding of your pregnancy timeline
• Useful for couples tracking fertility or understanding paternity windows

Did You Know?

• Conception typically occurs 11–21 days after the first day of your last period
• Sperm can survive inside the body for up to 5 days
• Implantation usually happens 6–12 days after ovulation

These biological timelines can vary from person to person — this tool offers a reliable estimate but not an exact science.

FAQs – Conception Date Estimator

Can I use this to determine paternity?

It can help estimate timing, but only a DNA test can confirm paternity. Use this as a timeline tool, not a legal reference.

Is this based on a regular cycle?

Yes, it assumes a 28-day cycle. If your cycle is longer or irregular, results may be slightly different.

Can I use this if I’m already pregnant?

Yes! If you know your due date, the tool can work backward to estimate when conception likely occurred.

Pro Tip:
Keep track of your cycle using our Period Tracker to get even more accurate predictions next time.

More Helpful Tools:

• Ovulation Calculator
• Due Date Calculator
• Pregnancy Trimester Tracker

Start Estimating Now

Enter your due date or last period date above and find out when your beautiful journey likely began. GlowMamaTools.com keeps it simple, helpful, and private — just the way it should be 💚