My Period Calculator

Calculate the date of your next expected menstrual cycle

Calculate here the date of your next expected menstrual cycle

Our period calculator is the quickest way for you to know when to expect your next menstrual cycle. You want to find out about the starting day of your next period? Simply enter the first day of your last period and the average length of your period cycle, then click on "calculate".

The menstrual cycle is the timespan between the first day of your period and the beginning of the next one. The period (or menstruation) itself usually lasts 2 to 5 days, with at least 3 days being widespread average.

Once you have entered the required data, the period calculator will immediately show you the estimated start dates of your next 12 periods. Be on the safe side and calculate your menstrual cycle now!

Facts about your period cycle

The average menstrual cycle varies around an average of approximately 28 days. Variations of up to 8 days are absolutely normal, whereas variations of 10 or even 21 days between the longest and the shortest menstrual cycle are considered irregular.

In medicine, the menstrual cycle always starts with the first day of your period. Although its length may vary, we assume an average of 4 days in which plasmine, an enzyme, prevents the blood from clotting.

On day 5 of your menstrual cycle, the usually 9-day long proliferative (or follicular) phase will begin. An increasing production of the follicle stimulating hormone (FSH) stimulates the ovarian follicles and will eventually produce an egg. This process is called ovulation. Sometimes, both ovaries release eggs, which will lead to fraternal twins in case of fertilization.

This ovulatory phase usually begins around the middle of your menstrual cycle and last for 3 to 4 days. If during this phase the egg is fertilized, it will immediately start developing an embryo and no new menstrual cycle will be initiated.

In the following luteal phase, the ovaries continue to produce significant amounts of hormones, most of all progesterone. This hormone increases the blood flow in and around the uterus and thus supports an early pregnancy. The luteal phase is usually marked by an increase in your basal body temperature. As the level of progesterone rises, the adrenals start to produce estrogen. This in turn leads to the beginning of the next menstruation and therefore to the start of another menstrual cycle.

During a typical menstruation, a blood loss of about 35 millilitres is common, but some women lose up to 80. The higher the blood loss, the higher the risk of iron deficiency.

Around two thirds of women suffer from acute uterine pain and cramps, which is called dysmenorrhea. Women younger than 25 are more likely to suffer from these severe pains.

Among the possible disorders that can occur, there is hypomenorrhea, which is marked by a flow of less than 10 millilitres. Menstrual cycles of less than 21 days are called polymenorrhea. Especially before the menopause, anovulatory cycles show menstruations without the production of any egg during the menstrual cycle.

Menstrual Cycle