You want to know the dates of your next period, ovulation or due date? You came to the right place. If you’re in a hurry you can go straight to our menstrual cycle calculator (click here) or Infographic with key information about calculating your period (click here).
Check the full table of content below.
Table of Contents
- Introduction
- Period & Ovulation Calculator
- How Do Menstrual Cycle Calculators Work?
- Using a Period Calculator
- How To Calculate Your Next Period & Ovulation Infographic
- Understanding the Menstrual Cycle Properly
- Understanding Your Next Menstrual Cycle and Fertilization.
- Some Important Information Regarding the Calculator
- Learn more
- Frequently Asked Questions
Introduction
If you want to stand the best chance of getting pregnant, then you need to know when you are ovulating. This is the time of the month when women are in their most fertile period. Ovulation usually happens around day 14 of the cycle [1]), while there is a greater chance of a sperm reaching the egg and fertilizing it.
However, one of the biggest problems and question that people have is knowing how to calculate their next ovulation date and when is the best time to aim for intercourse. This is where technology can come in handy. You can use an ovulation calculator, like the one below, to get a rough estimate of when you are going to ovulate next.
Ovulation & Period Calculator
Use this period calculator to calculate your next period (menstruation), fertile period, ovulation, and due date. To give you an estimate as to when those time frames are, please provide the requested information and press the Calculate button (results will be shown below, together with a fertility calendar):
When did your last period start?
How many days did it last?
How long is your cycle?
Below are the results based on the information you provided:
Your next menstrual period is expected to start on
Your next most fertile period is from to
If you conceive within this timeframe, your estimated due date will be
- Pre-Period
- Period Days
- Post-Period
- Peak Ovulation
Please note that this is only an estimation of your menstrual cycle
A period calculator is not the same as talking to a healthcare professional, so this is just to aid you in coming up with the most accurate calculation possible, on your own.
Also, keep in mind that these calculators will be useful to women with a fairly regular menstrual cycle. For women with irregular menstrual cycle tracking other ovulation symptoms or using an ovulation predictor kit might give more accurate results, all of which we’ll cover later one.
How Do Menstrual Cycle Calculators Work?
Menstrual Cycle Calculators vary in complexity. Some will ask you for information such as your average body temperature, as well as various other bits and pieces about what your body is currently going through.
While there are women who measure their basal body temperature, it’s not something that the everyday woman uses.
However, it is a rather accurate way (when done 100% correctly) to determine when a woman is ovulating.
Some feel that these types of cycle calculators are “overkill”, but for those who are using the basal body temperature to prevent and plan a pregnancy, they have this information handy.
If you aren’t into this type of strict monitoring, a simple calculator like the one provided here can give you really good results and help you plan.
Using a Period Calculator
The first thing that the period calculator will ask you is the date of your last period. With so many apps available now, this should be information that is readily available.
And just remember, when calculating your period, you use the first day of your last period. This was the beginning of your cycle.
If you don’t know the exact first day, calculate back from the last day however long it lasted, and start tracking now. Especially if you are trying to get pregnant.
Some will use a menstruation calculator to figure out when to expect their periods and when to expect PMS. PMS is due to the change in hormones that cause periods and pregnancy.
When you are pregnant or during your period, these emotional and physical symptoms subside [2]. Some women can then plan to change their diet a few days before they expect PMS and help to alleviate some of the symptoms.
The next piece of information that you will be asked for is the average length of time between your periods. This is the length of the menstrual cycle. Of course, the human body does vary wildly here, and whilst some months there could be 30 days between your period, others it could be as low as 25.
However, you are only after an average here. Being as accurate as possible is important as this will affect the results that you are given which can have a profound effect on when the calculator tells you is the ideal time to try for a child.
Finally, you will be given your results. Based on the information you provided, it will calculate when your next period is anticipated and also your fertile period which is when you stand the best chance to get pregnant.
How To Calculate Your Next Period & Ovulation Infographic
Understanding the Menstrual Cycle Properly
While you may already have a fair understanding of your own menstrual cycle, there are women who have cycle lengths that vary. Sometimes, your own cycle can be as short as 23 days on cycle and 28 or 30 days the next.
When a variation in menstrual cycle length occurs, it usually happens before you ovulate. This is referred to as the follicular phase which encompasses menstruation as well and ends when you ovulate [3]. A woman generally ovulates between days 12-16 of their cycle which is the start of the luteal phase [4].
There is a multitude of reasons as to why your period could be altered, be it stress or medications, even weight gain/loss or travel. Unless you think you are pregnant, it could be a myriad of reasons that have your period coming irregularly.
Understanding Your Next Menstrual Cycle and Fertilization
If you are trying to get pregnant you need to understand how the menstrual cycle works. The process starts when the thick lining of your womb starts to break up due to the decrease in estrogen and progesterone levels.
Without a sufficient amount of these hormones, your body will shed the lining and it will start to prepare for your next menstrual cycle.
However, if a sperm does make contact with and fertilizes the egg, it will close all pores to prevent more sperms from getting in there. The fertilized egg will stay in the fallopian tube for 3-4 days and then move to the uterus and attach to its wall, staying there for the long haul of pregnancy.
Your body will produce human Chorionic Gonadotrophin (hCG) or pregnancy hormone right away (which can be seen within 6-8 days by a blood test and can take about 2 weeks if not longer to be seen in urine tests) [5].
The body will continue to produce the required estrogen and progesterone hormones so that the womb lining will not be shed and the placenta can grow mature enough that it can support the pregnancy.
Some Important Information Regarding the Calculator
The period calculator above also comes with a fertility calendar. You can navigate through different months by clicking on the NEXT 2 MONTHS and PREVIOUS 2 MONTHS links. This allows you to plan and prepare for your fertile and menstrual periods in the upcoming months.
What you do need to remember though is that the information isn’t 100% accurate as it is impossible to predict the human body.
Your fertile period gives you a good range in when to have intercourse to potentially get pregnant. You can learn more about the likelihood of conception in this article.
That being said, the menstrual calculator is still an extremely useful tool. It provides a simple way of knowing when to anticipate your next period and when is the best time to try for getting pregnant.
This could be a huge help for those with busy schedules to plan their days to start their family.
Learn more
Want to learn more about your menstrual cycle? Find out how does the Fertility Calculator work or how to to calculate your period manually.
Want to know if you’re pregnant? Take this online pregnancy test, read more about the most common reasons why your period might be late or find out when it’s the best time to take a home pregnancy test.
FAQs
How do I calculate the length of my cycle?
Can I have sex during my period?
What is the average length for periods?
My period is really heavy; what can I do to change that?
Can I get pregnant if my periods are irregular?
How do I know if I need to see a doctor because my heavy periods?
Can I prevent PMS?
Do you have any other question about your period, ovulation, pregnancy or other related topics? Check out our Frequently Asked Questions page.
References
- Your Fertility. Women’s Guide to Getting the Timing Right [link]
- Mayo Clinic. Premenstrual Syndrome (PMS). [link]
- Better Health Channel. Menstrual Cycle. [link]
- see above #3
- WebMD. Pregnancy and Conception. [link]
- Eleanor Jones via Cosmopolitan. 10 Questions Period All Guys Want Answered [link]
- Playtex. Period 101. [link]
- The University of Iowa. Birth Control Pill Fact Sheet. [link]
- WebMD. Slideshow: Answers to Your Top period Questions. [link]
- see above #9





How will you know weather you are ovulating or not when you are not seeing any thing like drawing fluid
Hello Jacinta, generally no fluid happens just after ovulation. You can focus on other signs of ovulation- like many women feel twinge of pain or cramps in lower abdominal area (usually on one side only), Also, you can try using an ovulation predictor kit. Good luck!
Ok my last period was August 26 to august 31. I was supposed to get my period September 23 or 24. I had unprotected sex on the 10 of September with my bf then we broke up. Then I was with my ex September 18 and then I went back to my bf on the 20. I got what I thought was a period on I think the 13 14 15 of September but it wasnt a period. I’m a little confused about the father who can it be smh.
Erica, are you sure you are pregnant? Have you done any tests for it?
Comment Text*i had my period on 7 of March and I had sex on 18and 19 I my pregnant
Hi Jessica, have you missed your period in March? Or have you been experiencing any signs or changes in your body?
Comment Text* i had my last period on 29 February and ended on march 4, another one came this morning of which it should come on 25 of march and have 26days mensural cycle. Any help
Hi Alice, it’s perfectly normal for period to come early/late by 2-5 days. No worries.
I got my period march 22 (yesterday) I’m wanting to know if I will be back on it @the same day next month. I usually get it every 21 days and it lasts 5 days at the most but lately it comes early. I’m not sure how I’m supposed to calculate in between.
Hi MiraN, if you get your period every 21 days, then it is the number of days in your cycle. By that info., you should have your next period after 21 days to 22nd March, so it should be on 10th-12th April.
I had my period on 2nd March 2016 and had sex with my husband on the 22nd of March. Is there a chance of me getting pregnant?
Hi
I started my period 18th February. finished on the 24th. my estimated fertile window was 1st-5th March. when i wass estimated to ovulate i experienced light spotting for 2 days. My next period was due 17th Of this month and hasnt come yet. ive had sore breasts but no period pain. Could i be pregnant? im just unsure as i came off depo 1 year ago and been trying for 6 months now
Hello, sore breasts may be due to many reasons but as you are missing periods as well, I would suggest taking a pregnancy test. All the best!
I had a miscarriage on the 24th of last month and since then have been having sex with my guy but have not seen my period since. Am I pregnant? I’m not getting it.
my last period was feb 11 2016. i had unprotected sex on feb 21 , 25 , 28 march 19 and 21.
i didn’t get my period on the 10th.
Hi i had may period last feb 23. And supposed to be my period today. But we do it inside today. Is that safe?? Thanks
No it’s not. You should use protection if you don’t want to get pregnant.
hello i feel like i dont have a fix cycle sometimes its 28 days sometimes 30 days how can i know when I am ovulating ??? im trying to use some ovulation test at home but i dont know how much can be exact .. thank you
Hi Wafa, there are many ways to calculate ovulation. First, try charting your number of days in the period cycle. After a few months, you may notice a pattern.
Second, Cervical mucus- As you approach ovulation, the cervical mucus becomes plentiful, slippery, clear, and stretchy.
Try the ovulation test and see if you get more clarity. All the best!
Good morning, I saw my first period on the 22 of February 2016, that’s was my first period after not using a depo and my first period was normal. I was supposed to see my period on the 21st of March but I didn’t and I haven’t made love since my period.What does that mean? Or is it that my cycle is not 28 days?
My last period was 30th June to July 4 I had sex with my fiance on 15 16 17 and before 30th am already feeling weak and brest swallowing before I met my ex boy friend on 28 of July we had sex and I did pregnancy test 1st of August and went for scan 14 august am already 7weeks pregnant. Please tell me who’s the owner of the child
Hello, if you mean that you were 7 weeks pregnant on 14th Aug, the implantation should have been on 25th-29th June.
Hi , I had ovulation spotting which was one light pink spot on 10/3/16 (cd21) and my fertile days was 5th to the 10th of March , my cycles are 32 days and now no period when shall I test . Thank you
Hi Emma, when were your last period (in Feb)?
Hi I did two tests they were positive and my last period was 19/02/16 but not sure how far I am x
So I had my period on the 27th of February and it finished the 3rd or the 4th of March, the calendar says it supposed to come the 26 or the 27 of March and I have it the 22nd of march and I’m confused. The length of my cycle is 28 days.
It is normal for a cycle to change between periods. A period can come before or after it is due without it being a cause for concern.
I’m 36 years old, I have a 24-day cycle…Feb 27 – Mar. 2. My cycle started with spotting on the 3rd…normally week long. I has unprotected sex on the 7th…not sure about ovulation but lighter period I’m assuming on the 16th. But wasn’t expecting to see at until the 22nd.
Hi steffy, my friend had her period last feb 20 and had sex with my bestfriend on feb 29, she havent got her period yet but had this cramps like dysmenorrhea type. She was expecting it either march 19 or if ever march 25 but still her period didnt show up. She’s really worried we just graduated from college and her mom would die if shes pregnant.
Hi Joyce,
The cramps may be due to many reasons including pregnancy. The best way to know is using a test. Anyway, I hope your friend has gotten her period by now and doesn’t need the test. All the best for her!
Also, it’s never safe to have unprotected sex, not even during period. Always use protection.
Hey. My period ends on the 5th day, is it possible to ovulate on the 6th day? Because I saw something like gum in my private part but not too white. So can I conceive if I have sex on the 10th day?