Menstrual Cycle Calculator

Menstrual Cycle Calculator is an online calculator to predict the expected date of the next three menstrual periods. This calculator helps you find out if you have missed your period.
Menstruation indicates the start of reproductive life in women. The menstrual cycle may range from 21 to 45 days. The average length of a cycle is 28 days.
Key in your last menstrual period and average length of the cycles to chart out your next three cycles.

Find Expected date for next three mentrural periods.

Find Your Expected Date of Menstruation

First Day of Last Menstrual Period *
Average Length of Cycles *
* Required

What is Menstruation?

Menstruation  is a process of shedding blood from the uterus that usually begins for girls between the age of 11 and 14 and continues until menopause. At the time of menstrual period, a woman may experience abdominal cramping, lower back pain, bloating and sore breasts, mood swings, irritability, headache and fatigue.

Ten Interesting Facts about Menstrual Cycle that Every Women should Know

  • Most women bleed only about 80 ml or less during their periods(2 Trusted Source
    Heavy periods: Overview

    Go to source
  • At the time of ovulation, there may be slight spotting and/or pain.
  • Do you know why women don’t get periods during pregnancy? This is because during pregnancy, hormones that are released prevent endometrium from shedding off and ensure that it forms a thick lining of the uterus to provide protection and nourishment to the fetus(3 Trusted Source
    Menstrual cycle

    Go to source
  • The menstrual cycle starts with menarche and ends with menopause(4 Trusted Source
    Life-course origins of the ages at menarche and menopause

    Go to source
  • On average, a woman will have around 450 periods in her lifetime.
  • The body temperature changes throughout the menstrual cycle and is generally lower in the first part of the cycle and it then rises after ovulation and stays higher until a few days before the next period.
  • Pre-Menstrual Syndrome (PMS) is a medical condition with physical and emotional symptoms manifesting a few days before menstruation
  • Have you heard about ‘Menstrual Synchrony’ – This is a phenomenon described by psychologist Martha McClintock, in 1971, who observed that that the menstrual cycles of women living together (such as in dormitories) can synchronize over time. But this has not been further validated.
  • Menstruation tracking using a calculator or calendar is not new. Interestingly archaeologist discovered a menstrual calendar in France that dates back to 20,000 BC that was etched on a piece of bone.
  • Besides Humans other primates, bats, and the elephant shrew too have menstrual cycles.


Do you know what exactly happens during each menstrual cycle?

The female body undergoes 3 phases during every menstrual cycle. It includes the follicular phase, the ovular phase and the luteal phase.

Follicular Phase (Day 1-13):

  • The menstrual period starts as hormone (progesterone and estrogen) levels drop and the uterine lining (endometrium) breaks down. Bleeding may last for 3 to 5 days though it can vary from 2 to 7 days.
  • Around the 7th day, Follicle Stimulating Hormone (FSH) stimulates follicles containing eggs to develop on the ovary.
  • This is the time period during which one of the follicles matures and the inner lining of the uterine wall thickens and nourishes with blood and nutrients, thus making the uterus suitable for the implantation of a fertilized egg.

Ovular Phase (Day 14):

  • As the level of luteinizing hormone (LH) rises in the middle of the cycle, ovulation takes place.
  • During this phase, matured follicles rupture and release an egg from the ovary.
  • An egg can stay in the fallopian tube for only 24 hours. This is the best time to get pregnant.

Luteal Phase (Day 15-28):

  • The ruptured follicles develop into the corpus luteum that releases hormones (progesterone and estrogen) necessary for thickening of the endometrium. This is needed for the implantation of the fertilized egg.
  • If fertilization does not occur, the corpus luteum dies and hormonal levels drop, eventually making the endometrium to shed along with an unfertilized egg, resulting in the next menstrual period(5 Trusted Source
    Phases of the menstrual cycle

    Go to source

  • 1. Menstruation
    ( )
  • 2. Heavy periods: Overview
  • 3. Menstrual cycle
    ( )
  • 4. Life-course origins of the ages at menarche and menopause
  • 5. Phases of the menstrual cycle
    ( )
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