Ovulation & Pregnancy Calculator
How This Calculator Works
Based on well-established menstrual cycle science — quick, accurate, and private.
Enter Your Cycle Data
Input the first day of your last period and your average cycle length. Most women have cycles between 24–35 days.
We Calculate Ovulation
Using the standard luteal phase formula (cycle length minus 14 days), we estimate your most likely ovulation date.
Get Your Fertile Window
Your fertile window spans 5 days before ovulation to 1 day after — when sperm can survive and meet an egg.
Plan Up to 6 Months
See your ovulation dates and fertile windows for the next 6 cycles in one clear, printable table.
What Our Patients Tell Us
“I had been trying for over a year and always thought Day 14 was the magic day. The calculator showed me my cycle was 31 days — so I was missing my fertile window completely. That was the breakthrough.”
— Patient at Bavishi Fertility Institute
“I used it to figure out when to time intercourse after my IUI. Knowing I was in my fertile window gave us extra hope during that two-week wait. We got pregnant on our second IUI.”
— Patient at Bavishi Fertility Institute
“My cycles are irregular — 26 days one month, 33 the next. Entering different lengths helped me understand how much my window was shifting. My doctor said tracking this was the first step to understanding my PCOS.”
— Patient at Bavishi Fertility Institute
“The 6-cycle table was a game changer. My husband travels for work and we could actually plan around his schedule for the next few months. It felt like we finally had control over something.”
— Patient at Bavishi Fertility Institute
What this calculator helps you do
Find Your Fertile Window
Discover the best days for conception based on your cycle length.
Estimate Your Due Date
Track pregnancy progress with weeks, trimester milestones and baby size data.
Plan Your Next Steps
Use the estimates to time tests and appointments with more confidence.
Ready to feel confident?
Get expert guidance after your ovulation and pregnancy estimates.
Book a consultation with our fertility specialists to validate your cycle tracking, confirm your due date, or plan the next step.
Who Should Use This Calculator?
Just started trying to conceive
Learn when your fertile window actually falls — most couples are surprised by the timing.
Irregular cycle trackers
Adjust cycle length each month to see how your fertile window shifts with irregular cycles.
Timing IUI or natural cycles
Use the ovulation date estimate to plan intercourse or IUI timing with greater precision.
Planning around travel or schedules
The 6-month calendar helps you and your partner plan ahead when time apart is a factor.
Already pregnant
Switch to pregnancy mode to track your due date, trimester progress, and baby size week by week.
Understanding your cycle
Not ready to try yet? Use the tool to understand your natural rhythm before you start.
About This Tool
Fertility Calculators To Plan Your Pregnancy Journey
Use our expert-designed fertility calculators to estimate IVF success rates, track ovulation, understand your fertile window, and plan your journey to parenthood with confidence.
Find a Bavishi Fertility Institute Centre near you.
14 centres across 8 cities — premium fertility care, close to home wherever you are.