Ovulation Calculator: Estimate your most fertile days
Use this calculator if you want to get pregnant, understand your cycle, or know if you’re ovulating!
The typical menstrual cycle is 28 days long, but everyone is different. There are approximately 6 days when you are most fertile in each cycle, and use our calculator to pinpoint your most fertile days.
Is this Ovulation Prediction accurate?
Whether you’re trying to get pregnant, understand your cycle, or just want to know when you’re ovulating you need not just an ovulation calculator – but an accurate ovulation calculator.
There are plenty of methods for predicting ovulation, but cycles vary and one of the most accurate ways to predict ovulation is through hormone testing. Our hormones follow a predictable path before ovulation and this incredible device not only predicts ovulation but adapts to personal cycle variability.
Online ovulation calculators are sometimes lacking, the symptoms of ovulation can strongly vary, but hormone testing doesn’t lie and provides you with the greatest accuracy when it comes to predicting ovulation.
Have a look at Mira Analyzer – a palm-sized lab for your hormones.

It was designed by scientists and OBGYNs with exclusive technology to provide the most accurate results in ovulation prediction. Ultra-sensitive technology captures hormone changes with lab-grade accuracy. Not only do you get an accurate fertility calculator, you get the whole fertility picture based on your cycle. Mira is able to predict ovulation accurately, identify your full 6-day fertile window, confirm ovulation happened during a specific cycle, and know if your body’s fertility is healthy.
Mira gives you personalized results backed by AI that is trained and optimized on over 4 million hormone data points. It’s technology has analyzed 370k+ menstrual cycles and gets smarter every day!
In fact, a recent study of 89,288 cycles proved that Mira is 6x more accurate at predicting ovulation than the calendar method.
Unlike numeric OPK ovulation calculators, Mira uses lab-grade technology to analyze your hormone data with over 99% accuracy. Even if your cycles are irregular, Mira’s numerical readings provide a complete fertility picture by reading your LH, E3G, PdG, and FSH hormone levels. You don’t get false positives or missed peaks and avoid repetitive testing like you might have to do with other OPKs.

Even if you have regular cycles and a predictable period – studies have shown that online ovulation calculators are only accurate about 20% of the time.
Their results are based on the information you provide and work off of averages rather than numerical data. Your hormones can fluctuate and a simple online ovulation calculator has no way of knowing what’s going on inside your body.
You can also use the signs and symptoms of ovulation to predict when you will ovulate, but that’s only part of the picture. Confirming ovulation occurred is as important as predicting when it will happen, especially if you’re planning a pregnancy. Mira goes beyond simple predictions based on averages and provides a complete picture of your unique hormone data for trustworthy results of both predicting and confirming ovulation.
How Mira works
Regardless of when you ovulate, your hormones follow a predictable path before ovulation. OPKs determine ovulation based on a set of thresholds, whereas Mira tracks your actual hormone concentration levels.
Mira’s ovulation prediction is based on your personal unique hormone levels, rather than population averages. With hormone testing, Mira gives you an accurate prediction of your full fertile window and tells you when you are fertile, helping you prepare and understand your body more accurately.

Mira’s numerical hormone readings are especially helpful as an online ovulation calculator for irregular periods. As anyone with any cycle variability knows, it can be hard to get an accurate estimate of ovulation. OPKs can be especially faulty for women with irregular periods and tracking your period alone will not tell you if you’ve ovulated or not. With Mira, your daily levels of actual hormone concentrations are measured to detect when ovulation does (or does not) occur.
Regardless of what your goals are – Mira can give you fertility clarity by detecting higher hormone ranges and seeing how your hormones interact with each other. Mira picks up on your tiniest hormone changes and helps you discover the most fertile days in your cycle.
More than 26,000 people have already conceived with the help of Mira.
In the past, testing and tracking your hormone levels would require expensive and time-consuming trips to your doctor’s office for regular blood testing. But with Mira, you can use a hormone-tracking system that offers lab-quality results from home.
Mira’s hormone tracking system consists of the Mira Analyzer, testing wands, and the Mira App. Testing is a simple procedure that involves taking a urine sample, testing it with a testing wand, and then inserting the wand into the Mira Analyzer. Within 21 minutes of analysis, your exact hormone concentration results will be displayed on the Analyzer and the Mira App. The app provides insights about your complete fertility health and you can see your fertile window and predicted day of ovulation. Whether you’re trying to get pregnant or not, this information can help you plan sex with your partner to optimize your goals.

Tracking your hormones is a great way to stay on top of your fertility and reproductive health. Whether you are actively trying to conceive, plan a pregnancy, or simply gather more information about your fertility, with Mira you’ll have a clear picture of what’s going on inside your body each cycle.
