Your Fertile Window: The Best Time To Conceive
A woman can only get pregnant on a few days each cycle. Find yours with our free ovulation calculator and learn how to time things right.
Pregnancy is only possible during your fertile window each month.
There are simple ways to work out when you are ovulating.
Your chance is highest on the day of ovulation and the 2 days before.
When Are You Most Likely To Conceive?
The fertile window is the small handful of days in your cycle when pregnancy is possible. It is made up of the 5 days leading up to ovulation and the day of ovulation itself, because sperm can survive for up to about 5 days, while an egg lives for only around 24 hours after it is released.
The most fertile days are the 2 to 3 days just before ovulation. Having sex during this time gives you the best possible chance of conceiving. Since the exact day varies with your cycle length, the calculator below helps you pinpoint yours.
Ovulation Calculator
Enter the first day of your last period and your average cycle length to estimate your fertile window, ovulation day and possible due date.
Please pick the first day of your last period.
These are estimates based on an average cycle. Your body is unique, so use them as a helpful guide alongside ovulation signs.
Signs You Are Ovulating
Beyond the calendar, your body offers real-time clues. Watch for these around your fertile days.
Cervical Mucus
A few days before ovulation, mucus becomes clear, slippery and stretchy, like raw egg white. This helps sperm travel and signals your best days.
Ovulation Predictor Kit
These home urine kits from any pharmacy detect the hormone surge before ovulation. A positive result means you will likely ovulate in the next 24 to 36 hours.
Body Temperature
Your basal body temperature rises slightly just after ovulation. Tracking it daily over a few cycles helps you spot your personal pattern.
Working Out Your Cycle
Your cycle starts on day 1, the first day of bleeding, and ends the day before your next period begins. A normal cycle is anywhere from 21 to 35 days and can vary a little month to month. Ovulation usually happens about 14 days before your next period.
If your cycles differ in length, work out an average across three cycles to estimate your fertile days more accurately.
A Quick Example
Priya tracked her last three cycles: 28 days, 30 days and 29 days. To find her average, she adds them and divides by three.
Irregular Cycles?
If your cycles are very irregular and hard to average, don't worry. Simply having sex every 2 to 3 days across the month naturally covers your fertile window.
Your Chances By Timing
Having sex as close as possible to ovulation makes a big difference. Here is roughly how the chance of conceiving in a single cycle changes with timing (for an average, healthy couple).
These are average figures and also depend on age and overall health. By 12 to 24 hours after ovulation, the egg is no longer available, so that cycle's window has closed.
Myth vs Fact
A woman can get pregnant at any time of the month.
Pregnancy is only possible on a few days each cycle, because sperm survive about 5 days and an egg lasts only around 24 hours. The two must meet within that short window.
This calculator and information are a general wellness guide and are not a substitute for medical advice. Please consult a qualified healthcare professional for personalised care.