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Ovulation calculator

Ovulation calculator

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Average rating: 4 out of 5 star rating

If you're trying for a baby, knowing when you're ovulating can seem a bit confusing especially if your periods aren't regular. To stand your best chance of conceiving, you need to use an ovulation calculator.

An average woman's menstrual cycle is 28 days but cycles can range from 22 days right up to 36. Your menstrual cycle begins on the first day of your period and continues up to the day before you start your next one.

Use our free ovulation date calculator to find out when you're ovulating over the next six months.

Alternatively, follow these three steps to calculate your ovulation date and find out when you're likely to be most fertile.

Step 1: Your Menstrual Cycle

When your next period starts, make a note of the date. The following month, when your period comes again, make a note of this date, then count the days in between. This will give you your cycle length. You may need to do this for more than one month and take the average, especially if your cycle isn't regular. Remember also that coming off the Pill will reveal your true menstrual cycle.

Example:
Period starts = 1st January
Next period starts = 3rd February
Days in between (including 1st Jan but not 3rd Feb) = 33 days.

Your menstrual cycle length is 33.

Step 2: Your Fertile Dates

Using the chart, find the right number in the menstrual cycle length column (33 for the above example) and read across for your ovulation day and most fertile days.

Cycle length Ovulation Most fertile
22 Day 8 Days 7-9
23 Day 9 Days 8-10
24 Day 10 Days 9-11
25 Day 11 Days 10-12
26 Day 12 Days 11-13
27 Day 13 Days 12-14
28 Day 14 Days 13-15
29 Day 15 Days 14-16
30 Day 16 Days 15-17
31 Day 17 Days 16-18
32 Day 18 Days 17-19
33 Day 19 Days 18-20
34 Day 20 Days 19-21
35 Day 21 Days 20-22
36 Day 22 Days 21-23

Step 3

Work out your ovulation and most fertile dates. For the above example:

First day of last period = 3rd February 2008
Cycle Length = 33
Ovulation (19 days later) = 22nd February 2008
Most fertile (18-20 days later) = 21st and 23rd February 2008

Once you know your ovulation date, as a rule, you are most fertile the day before, during and the day after. However, because sperm can survive for up to seven days in the right conditions you could be fertile before and after these days.

N.B These figures are based on averages and should be used as a guide only. Days and dates may differ from woman to woman.

- Print out and keep version

Where next?
- 10 things you need to know about ovulation
- Recognising when you're most fertile
- Eat to get pregnant
- Facts about infertility
- Are you pregnant? Find out what symptoms to look for
- Are fertility home testing kits worth the money? Find out the facts

By Vicky Woollaston

Average rating:

4 out of 5 star rating

All pages in this article

  1. Ovulation calculator
  2. Print out and keep ovulation chart

Please leave a comment, tip or story in the box below

Sarah, 7 days

Hi all me and my partner have a 2 yr old daughter, and decided to try for a second. went to the doctor to get checked out as had no period for months, she told me i have PCOS, Took medication and i have had 2 periods on a 33 cycle, calender told me most fertile days will be 5th feb to 10th feb, anyone no of any really good postions and vitamins to ensure that we will definatly conceive?

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samantha, 14 days

hi everyone, ive got 3 girls who r 14 11 and 8. i had miriner coil in for 5 yrs then had it removed and a new 1 put back in same day. that was last feb. had that 1 taken out 12 nov 2009, so i could try get pregnant as i got new partner but then had a really bad bleed with clots etc on dec 25th so thinking this was my 1st period? im trying to have a baby, and just wondered if anyone as got caught straight after having coil out. just havent had my next period yet, and did pregancy test today and showed neg, so dont no when im ovulating???????????? please help

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laura, about 1 month

i have been trying to get pregnant for months now but my periods are irregular how will i no wen i am fertile

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charity, 3 months

since i had my first baby last two years now i have being trying but on june i be came pregnant and lost it 29th august and bleed for two weeks,so now i want to be come pregnant again so please help me.

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tiya, 4 months

hi i'm mother of a 1 year old boy, i want to get a baby girl!! the first day of the last ovulation is on 7th oct (today:)) could u please tell me the days to do sex to have a baby girl!!

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shiv, 5 months

Iam 41 for 9 months we tried ,no baby yet .we have done all examination ,both are ok . what I can do ,plaese give me advice. thanks

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EDDY, 7 months

hi,i wrote b4 and was hoping that some one will respond but no one did any i was due on friday that just past for my period but it did not show till yesterday evening it came but has already stopped,but i continue to have strange feelings at d lower part of my belly,even sometimes is as if i have a stomuch ache at in my stomuch,is it that am preganant,i what to be very sure b4 giving my boy friend d news,can somebody write me?

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able, about a 3months, 7 months

pls i want to be a mum, i used to take postenor-2 contraceptive about 1 and half year and i stopped taken the pill three months ago....i have been trying to get pregnant but still......pls help me!

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shiv, 7 months

hi had my coil out after 3years ov bein in on the 1st july 15 june was my 1st day ov my last period due on the 13 july nothin so far could i be pregnant yet !!! and i hav very regular period !!! do u think havin the coil out would hav messed my system up !!! is to soon to take a test !!!

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Iveta, 8 months

I also have the same problem as Amy, sometimes my cycle is 23 days, another months it's 26 days. We have been trying for a baby for over a year. Could you please help me how to figure out the ovulation calendar?

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chigo, 8 months

i am mother of two boys, i what my next baby to be a babt girl. pls help me in caculate my ovulaion cycle.pls tell me what to do b/c i into that problem now,iam confuse.

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bhavya, 9 months

please tell me how to do ovtlution sex ?

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Clare, 10 months

I have just found out that I am pregnant, and used your fertile calendar as a guide- so thank you very much, but can you tell me why my due date that the doctor gave me is 26th December, and my due date on your calendar is 5th January?

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Amy, 10 months

Hi i have a 11yr old child from a previous relationship and have now been trying to get pregnant for 18months, im not really sure how to calculate my cycle because if differs from month to month sometimes i come on right on my date others months up to a week late last month my cycle was 39days .Please help ive done everything i can think of possible

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Teresa juong, 12 months

iwould like to know if someone stayed for almost ten months with out pregnancy and that person when to the hospital and there was no transmitted deseas found and you are not concieving iwould like to know what cause and which step should be taken by that person inorder for her to get pregnant thanks By Teresa

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louise, about 1 year

Me and my hubby have been trying for a baby for 5 months now and nothing i have tryed Ovulation Calendars. If anyone has any ideas? i have also been taking folic acid HELP?

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eustin, about 1 year

You can use special computer programs to find the days when you are not fertile taking into account possible variations in your menstrual cycle. I've used one of such programs - "Advanced Woman Calendar" for 3 month. It supports Basal Body Temperature tracking. You can enter your temperature and program will give you all suggestions. You can read about it at http://www.softorbits.com/awc Also you can try another program - "Gegamon Menstrual Calendar".

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preeti, about 1 year

hi friends we are all in the same boat at the moment i have been for three years, i was on pill for a year came out of it year ago and since then me and my hubby are desperate to have a child. my periods are regular i went to gynecolog got all the test done and still nothing, test came out clear say we both are ok with no problems buy why i cant conceive i dont know. can anybody help please. i really wanna be a mum by next year.

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blessing, about 1 year

hi ally don't worry you will get pregnant soon just truast in god because , if god gave you a husband why he not give you the childrean because married is a bless,so god will give you a baby just trying God answer all your prayers.

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Kathy Roe, about 1 year

Everyone that has had a child has been blessed. I am 37 now and been trying to have a kid since I was 22. May God answer all your prayers in conceiving. I am starting to think I been cursed. :(

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donna, about 1 year

i have 1 child who is now 6 me and my boyfriend have been trying for are second child now for nearly 3 years i was on the depo injection for some time but did think everything would be back to normal now i did fall pregnant about 5 months ago but i miscarryed we are very desperate now and really want to bring a second child in to are family any one with any advise are ideas ?

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Rathana, about 1 year

I am trying to get a baby 9 monthes already but now still not yet have. I am not regular cycle. Ex last month my cycle was on 3rd and for this month is on 6rd. I want to know which date should i have a baby.

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Ally, about 1 year

my and my husband have been trying for a baby for over a year and still nothing has happend. I have two children from a previous relationship but after my youngest child i fell pregnant at a bad time and ended up having an abortion, i then started seeing my husband and we got married and have decided to expand our family but can't seem to get pregnant we are quite a healthy couple i go to the gym 3-4 times a week and our sex life is great too but just wondered if anyone had any tips or sugestions on what i could do more?? thanks xx

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Crystal, about 1 year

I have been with my boyfriend for 10 years now and we finally have decided to have a baby...We have been trying for 3 months now and nothing..!!!! I chart my cervical mucas and use OPK's and have sex on the days I am suppose to I think (My cycle varies from 28-29-30-31 days every months so its kind of hard...Can anyone help??? I am now very ready to be a mom.....

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nadia, about 1 year

I have 2 children age 6 and 3 and fell pregnant first try,I have been tring for 6 months with no luck, i had hysteroscopy to remove iucd in 2006 and i don`t know if it has some thing to do with it.good luck for any one how is trying.

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louise, about 1 year

I had an abortion start if April 08, and I regret it everyday since, there are a few reasons I did what I did including me listening to a few people I wish I didn't now. I hate myself for what I did because since I had it all I want is to have a baby with my long-term bf. Thats all I want. We have been trying for a baby ever since and nothing....Im worried something is wrong. I am worried about infertility after my terminantion, please help me. Thanks.

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Sam, about 1 year

Hi, Me and my hubby have been trying for a baby sinxce April, but we haven't had much luck yet. We are active couple and keep on trying but now i'm just feeling slight disappointment that nothing is happening. I have regular periods each month, but my cycles vary every month, which of course doesn't help. Does anybodu know if my weight issue could be a problem. I'm 27, 5'2 and i weight around 12 stones? Any one please advice. Thanks, :(

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net, about 1 year

thank you so much for this article and the ovulation calculator. i have always wanted to understand better how it all works and to get the correct dates to make babies. now that i know what my cycle is like, at least i know im going somewhere! million of thanks again!

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lisa, about 1 year

i have 2 children from a previous relationship and i have been triying for a few years to get pregnant and absolutely nothing until this feb of o8 i fell pregnant purely this time by accident i was supposed to have surgery in march of 08 and was late getting my period so low a behold got a pregnancy test and it was positive only for it to be followed by a misscarriage and d and e on april 10. i was so devestated. so i again tried to fall pregnant again for may and was late and dissapointed when i got my period this morning. don't understand whats going on thought you were more fertile after a miscarraige this is the second month since my loss. anybody have any ideas we had relations all around ovulation day and nothing. i can't wait another 3 yrs to get pregnant again that was horrible.

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lauren, about 1 year

I chose to have an abortion around 3 months ago, relationship was difficult and i thought it was for the best but i have come to realise that i want a baby more than anything.....i am wondering if you could give me advice on tips to get pregnant....??i am worried also about infertility after my terminantion. thanks

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Michelle, about 1 year

hiyaa a jus found out about 3 weeks ago i am now about 10 weeks pregantan am so woried i hope my baby is healthy and normal. i want a boy and have a few names in mind me and my boyfreind are so happy we are so exited. i cant wait for my scan so that i can have some idia to weather my baby is in perfect health. good look to all uss pregnant wimon out there ayeee!!!! xxxxxxx

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solange, about 1 year

thanks alot for this, but i still dont realy understand how to count my cycle, iam still confuse help me let say last month i have my period on the 26of marh , next month on the 21 of aprit plaese can u explain me how to count it ? please

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clare, about 1 year

i had an abortion about a year ago and have been trying ever since and nothing has been happening...i got pregnant first time last year, but as i was going thew a divorce it was unsuitable...do you think that abortion may of damaged me or anything?

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sal, about 1 year

good

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oladapo adedamola, about 1 year

well i don,t know if am pregnant now or not because my last period first day is 28 january and i dont know how to calculate it to give me the right result i will really appreciate if you can help me out

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amy pines, about 1 year

i keep ovulating on diffrent days each month

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Judith, about 1 year

Hi Natalie, l have just conceived after 5 months of trying the only thing i did different this month was start taking Agnus Castus tablets from the health shop coincidence maybe all my previous pregnancies like yourself happened first try round but i have been struggling with this one til now(touch wood) hubby says don't forget afternoon delight aswell.Also been taking the folic acid vitamin tablets in readiness all along.Good luck anyway

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natalie, over 2 years

i have 2 children from a previous relationship, and i fell pregnant on the first try with both of them! however my new partner and i have been trying to get pregnant now for over 5 months and still nothing? any body have any ideas? I am desperate and will try anything!

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