Ovulation Calculator

Enter the first day of your last period and menstrual cycle length to know when you may ovulate.

Enter first day of your last period

Average Length of Cycles (Days)

Created By:

Emily Smith
Emily Smith

Emily Smith

Emily holds a Bachelor's degree in Computer Science from a renowned university. She continued her education with specialized courses in mathematics and data analytics.

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Verified By:



Adam holds a Master's degree in Public Health with a focus on reproductive health and epidemiology.Adam has worked closely with healthcare providers and policymakers to develop evidence-based strategies.

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Based on Research By: Wilcox AJ, Dunson D, Baird DD. Fertile Window TimeBMJ;

Note: This tool does not suggest any medical advice. It uses your past cycles to estimate ovulation, but cannot pinpoint the exact date. This tool is used for informational purposes only and does not constitute medical advice. The calculator is not to be considered to prevent pregnancy. The results generated by this calculator depend on menstrual cycle length that might vary from woman to woman. If there’s any medical or health emergency, you have to make an immediate visit to your DOCTOR.

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“Ovulation Calculator”

Use this ovulation calculator that tells when you’re ovulating to figure out your most fertile days. Understanding the fertile window is crucial, this is the right time when sexual intercourse is most likely to result in pregnancy. So, get the ovulation calendar with this tool to find your fertile window and maximize your chances of getting pregnant. 


You can use this calculator (predictor) to calculate:

  • Ovulation date: The day when the egg is released on which the chance of conception is high
  • Next period date: When your next period is likely to happen
  • Intercourse window: Also known as fertile window that includes the days when you are most fertile
  • Ovulation calendar: A complete schedule that highlights your period and fertility window
  • Important dates: Next six menstrual cycle details and corresponding fertility dates (including ovulation)


Ovulation Symptoms:

  • Rise in basal body temperature (about 1/2 - 1 degree Fahrenheit) due to increased level of progesterone hormone
  • Bloating around the abdomen area
  • Mood swings
  • Heightened sense of smell
  • Changes in cervical mucus (Usually becomes more slippery and stretchy like egg whites)
  • Tenderness in breasts
  • Libido Boost that causes increased sex drive

Pregnancy Tips:

These are the tips for getting pregnant:


  1. Track Ovulation: Use the ovulation tracker to track when you are most likely to ovulate. Remember that ovulation occurs 14 days before your next period. And the tool can help you predict the fertility window during which your conception chances are maximum, based on your menstrual cycle length.
  2. Timing Intercourse: Try having intercourse every other day during your fertility window.
  3. Prenatal Vitamins: Start taking prenatal vitamins 1 month before you have intercourse. These vitamins provide necessary nutrients for both you and the developing baby.
  4. Manage Stress: Try to practice relaxation exercises like Yoga, etc. to manage your stress.
  5. Partner's Health: Rather than women, fertility also depends upon men’s health. So make sure your partner does not smoke, drink alcohol, or caffeine, or eat unhygienic food that can disturb the sperm's health.
  6. Healthy Lifestyle: Try to balance your diet and workout routine.
  7. Consult Your Doctor: Visit your doctor if you do not get success after months of conception efforts.

What Is an Ovulation?

Ovulation is a natural biological process in a woman’s body during which a mature egg is released from one of the two ovaries. It happens around 14 days before the next period starts, but it can take place anywhere from day 11 to day 21 of your cycle. But it may not occur exactly in the middle of the cycle, even with regular cycle length.


It is indicated as an important part of the menstrual calendar and plays a key role in pregnancy.


How Long Does Ovulation Last?

An ovulation itself lasts within 24 hours after it starts. During ovulation, the released egg travels down the fallopian tube where it stays for about 12 to 24 hours for fertilization. If fertilization doesn't happen during this span, the egg dissolves in the uterine lining that sheds. This results in menstrual bleeding that occurs about 2 weeks after ovulation ends, which is known as a period.

Remember that ending ovulation does not mean you can't get pregnant. Ovulation occurs within a fertility window that is a 5-day process (the 5 days leading up to ovulation and the day of ovulation itself). If you have intercourse within these days, the male sperm remains in the female reproductive tract for about 5 days. This increases the chances of sperm and egg meeting for fertilization.

How Many Times a Day Should I Check If I'm Ovulating?

It depends on the method you are using to check. Methods like basal body temperature or ovulation predictor kits require multiple checkings based on the instructions given with each method.


The following table may help you predict your ovulation for the general methods:


Method How often to check
Basal Body Temperature (BBT) Once a day, first thing in the morning
Cervical Mucus Daily
Ovulation Predictor Kits (OPKs) Once or twice a day, depending on brand and cycle regularity. Follow test instructions.


You can also use this ovulation calculator to check the day around which you might ovulate.

Menstrual Cycle and Ovulation:

A menstrual cycle is a complicated female cycle that continues from puberty until menopause. It is controlled by the hormonal cells that cause periods and ovulation.

An average menstrual cycle has four distinct stages, including:


The menstrual cycle starts with this phase during which the lining of the uterus sheds and causes a period. This happens if pregnancy does not occur. Your period contains tissues, blood, and cells from the uterus lining. The duration for this phase is about 3-7 days.

Follicular Phase:

This is the longest phase of the menstrual cycle which starts from the 1st day of the period and lasts until 14 to 21 days. During this phase, the female ovaries prepare the egg that is released later during the ovulation. The uterus lining also thickens during this phase which prepares the female’s body for pregnancy.


This is the phase during which the pregnancy chances are at peak if you have intercourse (Refer to the ‘What is ovulation’ section for more details).

Luteal Phase:

This is the last stage in the menstrual cycle during which the cells in the ovary release Progesterone and a little bit of Oestrogen. It leads to the thickening of the uterus lining for pregnancy.

If fertilization occurs, the corpus luteum continues to produce Progesterone that helps to maintain the thick lining of the uterus. And, if it does not, the corpus luteum dies, and the level of progesterone drops. This causes the uterus lining to get thin and shed and the period starts again.

Menstrual cycle in female body

Frequently Asked Questions

Can I get pregnant just after my period has finished?

Yes, but it is very unlikely to get pregnant right after your period ends. It depends on the:

  • Sperm survival
  • Ovulation timing

Typically ovulation occurs in the middle of your menstrual cycle, if you have intercourse right after your period, it means that sperm would likely not survive long enough to meet an egg that is released during ovulation. To increase your chances of conceiving, find your fertile window with this fertility calculator.

When to Visit a Doctor?

You need to visit a doctor in case of

  • Heavy bleeding during the periods
  • Sudden changes in cycle lengths (due to fever, nausea, etc)
  • Severe pain that lets you inhibit daily life activities
  • Bleeding between periods
  • Longer or irregular periods
  • Unusual blood clots

Can irregular periods cause late ovulation?

Yes, irregular periods can be caused by ovulation occurring late in your cycle. It is caused due to:

  • Weight Fluctuations
  • Stress
  • Breastfeeding
  • Medical Condition (PCOS and hypothyroidism)

Due to these causes, changes in menstruation are temporary.

When should I take a pregnancy test after I ovulate?

You should try taking a pregnancy test at least 12-14 days after the ovulation. During this period of time, the hCG (human chorionic gonadotropin) hormone builds up to detectable levels in your urine, indicating the possibility of pregnancy.

Traces of hCG can be detected as soon as eight days after ovulation, but taking a pregnancy test too early might result in a false negative result.

Does an ovulation calculator work if I have irregular periods?

No, the calculator is not suitable for women with irregular periods. This is because ovulation can happen on different days each month, which makes the tool estimations way off.