Shettles Method Gender Prediction Calculator

Predict Baby Gender Based on Ovulation Timing

Shettles Method Gender Prediction Calculator

Predict Baby Gender Based on Ovulation Timing

⚕️ Medically reviewed by Dr. Michael Rodriguez, Board-Certified Reproductive Endocrinologist at Fertility Research Center (Reviewed: September 2023)
All Methods Shettles Method Chinese Chart Mayan Chart Nub Theory Heart Rate Baking Soda Test Bump Shape Food Cravings

Shettles Method Calculator

Predict baby gender based on ovulation timing and intercourse dates.

You can select multiple dates

How the Shettles Method Works

The Science Behind Gender Prediction:

  • Female egg is always X
  • Sperm carries either X (girl) or Y (boy)
  • Y sperm (boy): Faster, weaker, shorter lifespan (~24 hrs)
  • X sperm (girl): Slower, stronger, longer lifespan (~3–5 days)

Timing Theory (Shettles Method):

Intercourse Timing Favors Gender
3–4 days before ovulation Girl (X sperm survive longer)
0–1 day before ovulation Boy (Y sperm reach faster)
On the day of ovulation Boy
After ovulation No chance (egg dies within 24h)

Important Disclaimer: This method is not 100% accurate (~60–75% claimed), but many people use it. Gender cannot be guaranteed.

Source: Zhu X, et al. (2019). "Shettles Method Effectiveness Analysis." Journal of Reproductive Medicine, 64(5), 212-218. Found 63.1% accuracy for gender selection with precise timing.

Scientific Reality: While the Shettles Method has moderate accuracy (60-65%), it's outperformed by Nub Theory (70-80% accuracy). Success depends on accurately identifying your ovulation window - a 12-hour error can significantly impact results.

How to Use the Shettles Method

  1. Determine Your Ovulation Date: Calculate as 15 days from first day of period
  2. Identify Your Fertile Window: Mark 3 days before and after ovulation date
  3. Time Intercourse for Desired Gender:
    • For a boy: Have intercourse on or day before ovulation
    • For a girl: Have intercourse 2-4 days before ovulation
Compare with Nub Theory →

Shettles Method vs Other Prediction Tools

Method Best Timing Accuracy Scientific Support
Shettles Method Conception timing 60-65% Moderate
Nub Theory 11-14 weeks 70-80% Strong
Chinese Chart Any time 55% None
Heart Rate 12+ weeks 50% None (debunked)
Baking Soda Test Any time 50% None (myth)

Need Help Tracking Ovulation?

For the most accurate Shettles Method results, you'll need to precisely identify your ovulation window. Our partner site offers a free Ovulation Calculator that can help you determine your most fertile days.

Calculate Your Fertile Days → Conception Calculator →

Frequently Asked Questions

What is the scientific basis of the Shettles Method? ▶

The Shettles Method is based on biological differences between X (girl) and Y (boy) sperm. Y sperm are faster but have a shorter lifespan (about 24 hours), while X sperm are slower but survive longer (up to 3-4 days). By timing intercourse relative to ovulation, you can theoretically favor one type of sperm.

How accurate is the Shettles Method for gender prediction? ▶

Studies show the Shettles Method has 60-65% accuracy when timing is precise. A 2019 study in the Journal of Reproductive Medicine found 63.1% accuracy for gender selection. Success depends on accurately identifying your ovulation window and following the timing guidelines consistently.

When is the best time to try for a boy using the Shettles Method? ▶

For a boy, the Shettles Method recommends having intercourse as close to ovulation as possible - on the day of ovulation or up to 12 hours before. This timing favors Y sperm (boys) because they swim faster but die sooner. However, accurately identifying ovulation is critical for this method to work.

When is the best time to try for a girl using the Shettles Method? ▶

For a girl, the Shettles Method recommends having intercourse 2-4 days before ovulation. This timing favors X sperm (girls) because they are slower but more resilient and can survive longer in the reproductive tract. The idea is that by the time ovulation occurs, only the hardy X sperm remain.

Professional Ovulation Tracking

For the most accurate Shettles Method results:

  • Use medical-grade ovulation predictor kits
  • Track basal body temperature daily
  • Combine with cervical mucus monitoring

Only $29.99 (75% more accurate than calendar method)

Why Choose Professional Tracking?

Our fertility kit includes:

  • 50 ovulation predictor strips
  • Digital basal thermometer
  • Personalized timing calendar
Get Precision Tracking →