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Online Ovulation Calculator

One of the most important, and least intrusive ways you have to boost your chances of conceiving quickly is to know when you’re ovulating. You stand the best chance of getting pregnant if you try in the ‘fertile window’ around the date you ovulate. When you ovulate – when your ovaries eject a mature, fertile egg into the fallopian tubes – the clock starts ticking. That egg is fertile for a maximum of 24 hours (or less depending on your reproductive health), so you need to ensure it encounters equally fertile sperm within that 24 hours in order to give yourself a chance to get pregnant.

One of the less stressful ways of finding out when you’re ovulating is to use an online ovulation calculator. These are less intensive than apps that you download to your phone, or software you have to buy and install – they just ask for a few inputs and give you an answer in a few seconds, based on their records!

It sounds like an easy answer, but is it helpful? To answer that we need to look at how they work.


Most online ovulation calculators ask for only a couple of inputs: the date your last period started, and the length of your cycle. If you know this information, then it can give you an indication of where you are in your cycle and when you’re due to ovulate almost immediately. There are, however, a few obvious drawbacks.

Tracking Your Cycle

If you know the date your last period started and the length of your menstrual cycle in days then you already have all the information you need to say whether you might be ovulating. And of course, if you haven’t been tracking that information, you simply can’t use a calculator like this! So, it does require some preparation: at the very least you need to note the dates of your period across two or three months – this means you know the day your most recent period started as well allowing you to be confident about how long your cycle is.

Cycle Length

The other major problem with this method of ovulation prediction is that it simply can’t take account for women who have irregular menstrual cycles. This is simply how some bodies operate: while some people have a regular cycle of 28 days – or 21, or 35 at the extreme – others can have a short cycle, followed by a longer one, unpredictably. This can also be a symptom of issues like PCOS or some thyroid problems, which have other fertility effects too.

A Solution for Everyone

Whether your cycle is as regular as clockwork, or extremely hard to pin down, OvuSense is able to get to the truth behind the disruption. Our system uses a specialised sensor to measure your Basal Body Temperature right through the night, to get an accurate picture of where your body is in its menstrual cycle and provide you with the predictive power you need.

Find out more about core temperature technology and fertility here