Menstrual Cycle Calculator

A menstrual cycle begins on the first day of your monthly cycle or period and ends on the day before your next period. Although the average length of a menstrual cycle is 28 days, the same varies from woman to woman. Women may experience shorter and longer cycles of 23 to 35 days, and this is considered normal unless one is suffering from underlying health conditions.

A woman may experience different signs and symptoms before her periods due to the changing hormones. The following are some common signs that indicate that your period is coming —

• Mood swings: You may notice minor or major mood swings a few days before your menstrual cycle. Some common mood changes include anger, irritation, anxiety, extreme fatigue and sadness.

• Tender and heavy breasts: Thanks to hormonal changes in the body, your breasts may feel tender, swollen and heavy right after ovulation. This is termed cyclical breast pain. The pain and tenderness go away a few days after you get your periods.

• Abdominal cramps: You may experience cramps or pain in the lower belly a couple of days before your period. The same may last for about 2-3 days.

• Gastrointestinal discomfort: Periods can also cause a range of digestive issues, such as bloating, flatulence, constipation and diarrhoea.

• Headache: The changes in oestrogen level can cause headaches before periods, especially if you experience migraines often.

• Acne breakouts: High progesterone levels before periods make the skin oilier and cause acne breakouts.

In addition to these, you may experience lower back pain before your periods and crave certain foods, such as chocolates.

Pregnancy is a common reason for a late or missed period. Therefore, it is important to take a pregnancy test after 21 days of intercourse. Taking a test sooner may not show correct results.

However, your period may also get delayed due to excessive stress, changes in body weight, strenuous exercises, hormonal imbalances, birth control pills and certain underlying health conditions. Some common signs and symptoms of late periods are pain in the lower abdomen, clear milky white discharge, breast tenderness, nausea and headache.

The period calculator calculates the menstrual cycle by using the following information:

• The starting date of your last period
• The length of your period (the number of days for which you bleed every month)
• The length of your menstrual cycle or the number of days between one period and the next.

Once you have entered the required information, click or tap on the “Track It” option to know your period date. Alternatively, you can also calculate your period date using the following information:

• Make a note of your average monthly cycle duration, i.e., the number of days between the beginning dates of two periods.
• Add this monthly cycle duration to the date your last period began. This will give you the tentative date of your next period.

For example:
• Your monthly average cycle duration — 28 days
• Beginning date of your last period – 25th January
• Therefore, the tentative date of your next period will be: 25th January + 28 days = 22nd February

The period calculator studies your period data history to calculate your menstrual cycle. The calculator’s results are almost accurate for women with regular periods.

Although a typical period cycle is 28 days, the same varies from one woman to another. While some women have a shorter cycle of 21 to 23 days, for others, it may be longer than 35 days. Many women also experience irregular periods, i.e., their menstrual cycle length is different every month.

If you have irregular periods, it can be difficult for the calculator to predict your next period. Therefore, the data shared by a period calculator may not be accurate. However, you can still use the calculator to get an overview of your periods and understand how irregular they are. Studying the history of your period data will help you get a rough idea of your next period date. It can also come in handy during your gynaecologist appointments.