Ovulation Calculator

Knowing when you are likely to ovulate can improve your chances of becoming pregnant. Simply enter the date of your last period and the number of days, on average, that your period lasts, and the fertility calculator will automatically estimate your most fertile days.

When was the first day of your last menstrual period?

How many days are there in your cycle?

How Ovulation Works

It may be helpful to track your menstrual cycles as anticipating your most fertile time is very important in helping to plan your pregnancy. Ovulation normally occurs 10-16 days before the start of your next period. You are most likely to get pregnant within a day or so of ovulation.

Your ovulation should be somewhat easy to predict depending on how regular or irregular your menstrual cycle is. However, trying to plan sex around the time you are ovulating can be stressful, so the National Institute for Health and Clinical Excellence (NICE) advise, that for the best chance of success, you should have sex every 2-3 days throughout the month.

The process of ovulation occurs when a hormone produced by women called luteinizing hormone (LH) is released, travels through the bloodstream to your ovaries and causes the egg to break through the ovary wall within 24-36 hours and begin its journey down the fallopian tube for fertilization. If the egg is not fertilized it dissolves after 24 hours, leading to menstruation. A day or two before you ovulate, your output of LH suddenly increases, often causing an increase in your body temperature, the sign ovulation is about to begin.

Hormone tests are the most accurate way to find your ovulation date, but other products such as ovulation kits or thermometers can help you discover when you're most fertile time is. Women are normally born with millions of immature eggs waiting for the ovulation process to begin, but only one egg is usually released during the ovulation cycle. Your cycle can be affected by stress, illness or changes in your normal routines.

Common Signs of Ovulation

The two most common signs of ovulation are changes in your body temperature and cervical fluid. One way to check your ovulation is to take your temperature as soon as you wake up in the morning. If you have ovulated your temperature should be slightly higher than the average of the days before. This change in temperature signals you have ovulated, not when you are going to ovulate.

Ovulation kits can also be used to help detect when your LH surge occurs. The mucus produced by your vagina and cervix changes its characteristics due to the fluctuating levels of oestrogen and progesterone. As ovulation approaches, the mucus that is normally thick and sticky becomes thin and clear. This allows the easy passage of sperm through the cervix. After ovulation the mucus becomes thicker again. Monitoring the changes in vaginal mucus can be helpful when determining your ovulation time.