Period Calculator
Track your menstrual cycle, predict future periods, and identify your most fertile days with our comprehensive period calendar and ovulation calculator.
Period Information
Most periods last 2-7 days. Average is 5 days.
Cycle length is from day 1 of period to day 1 of next period.
Understanding Your Menstrual Cycle
Knowledge about your menstrual cycle empowers you to better understand your body, track your fertility, and recognize what's normal for you. Learn the science behind your cycle.
What Is the Menstrual Cycle?
The menstrual cycle is a monthly series of changes your body goes through to prepare for potential pregnancy. It's controlled by a complex interaction of hormones and typically lasts between 21 to 35 days, with 28 days being the average. The cycle begins on the first day of your period and continues until the first day of your next period. This natural process usually starts between ages 12 and 15 and continues until menopause, which typically occurs around age 52.
Why Tracking Matters
Health Awareness
Regular tracking helps you identify your normal pattern and quickly notice any unusual changes that might require medical attention, such as irregular periods, excessive bleeding, or severe pain.
Fertility Planning
Understanding your cycle is essential whether you're trying to conceive or avoid pregnancy. Knowing when ovulation occurs helps you identify your most fertile days.
Symptom Management
Predicting your period helps you prepare for potential symptoms like cramps, mood changes, or fatigue, allowing you to plan activities accordingly.
What's Considered Regular?
A regular menstrual cycle is one where the longest and shortest cycles vary by less than 8 days. While the "textbook" cycle is 28 days, normal cycles can range from 21 to 35 days.
Normal Cycle Ranges:
- • Cycle length: 21-35 days
- • Period duration: 2-7 days
- • Blood loss: 30-40ml (2-3 tablespoons)
- • Variation: Less than 8 days between cycles
The Four Phases of Your Cycle
Your menstrual cycle consists of four distinct phases, each characterized by specific hormonal changes and physical effects. Understanding these phases helps you recognize what's happening in your body throughout the month.
Phase 1: Menstrual Phase (Days 1-5)
This is when your period occurs. The uterine lining (endometrium) that thickened during the previous cycle breaks down and sheds, resulting in menstrual bleeding. Hormone levels (estrogen and progesterone) are at their lowest during this phase.
Common experiences:
Cramps, lower back pain, fatigue, mood changes, bloating, and headaches. These symptoms are caused by prostaglandins, hormone-like substances that trigger uterine contractions.
Phase 2: Follicular Phase (Days 1-13)
Beginning on day 1 of your period and lasting until ovulation, this phase involves the maturation of egg follicles in your ovaries, stimulated by follicle-stimulating hormone (FSH). The pituitary gland releases FSH, prompting your ovaries to produce 5 to 20 small sacs called follicles, each containing an immature egg.
What you might notice:
Rising estrogen levels cause the uterine lining to thicken, energy levels typically increase, skin may look clearer, and you might feel more sociable and confident as estrogen peaks.
Phase 3: Ovulation Phase (Day 14)
Ovulation occurs when a surge of luteinizing hormone (LH) triggers the release of a mature egg from the dominant follicle. This typically happens around day 14 of a 28-day cycle, but timing varies. The egg travels down the fallopian tube, where it may be fertilized by sperm. This is your most fertile period.
Ovulation signs:
Slight increase in basal body temperature (0.5-1°F), clear stretchy cervical mucus resembling egg whites, mild pelvic discomfort (mittelschmerz), increased libido, and heightened sense of smell.
Phase 4: Luteal Phase (Days 15-28)
After releasing the egg, the ruptured follicle transforms into the corpus luteum, which produces progesterone to maintain the uterine lining. This phase typically lasts 12-16 days. If pregnancy doesn't occur, the corpus luteum breaks down, hormone levels drop, and menstruation begins.
PMS symptoms may include:
Breast tenderness, bloating, food cravings, mood swings, irritability, fatigue, and sleep changes. These premenstrual symptoms affect up to 75% of women and are caused by fluctuating hormone levels.
Common Period Problems & When to Seek Help
While some variation in your cycle is normal, certain symptoms warrant medical attention. Recognizing the difference between normal discomfort and potential health concerns is important for maintaining reproductive health.
Warning Signs
Heavy Bleeding
Soaking through a pad or tampon every hour for several hours, passing large blood clots, or periods lasting longer than 7 days may indicate menorrhagia and require evaluation.
Severe Pain
Pain that interferes with daily activities, doesn't respond to over-the-counter medication, or worsens over time could signal endometriosis or fibroids.
Irregular Cycles
Cycles varying by more than 8 days, missing periods (when not pregnant), or periods occurring more frequently than every 21 days should be discussed with your doctor.
Managing Discomfort
Heat Therapy
Apply a heating pad or hot water bottle to your lower abdomen to relax uterine muscles and reduce cramping pain naturally.
Exercise
Light to moderate exercise releases endorphins, natural pain relievers that can reduce cramps and improve mood during your period.
Diet & Hydration
Stay hydrated, reduce salt intake to minimize bloating, and consume anti-inflammatory foods like omega-3 rich fish, nuts, and leafy greens.
Lifestyle Factors Affecting Your Cycle
Your menstrual cycle doesn't exist in isolation—it's influenced by various lifestyle factors, stress levels, and overall health. Understanding these connections helps you maintain regular, healthy cycles.
Stress Management
High stress levels can delay or skip ovulation entirely, leading to irregular periods. Chronic stress affects the hypothalamus, the brain region that regulates reproductive hormones. Practice relaxation techniques, adequate sleep, and stress-reduction activities.
Weight & Nutrition
Both underweight and overweight conditions can disrupt your cycle. Body fat produces estrogen, so too little or too much can affect hormonal balance. Maintain a healthy weight through balanced nutrition and regular exercise for optimal cycle regularity.
Exercise Balance
While regular moderate exercise supports healthy cycles, excessive intense training can suppress ovulation and cause missed periods. Athletes and those with very low body fat may experience amenorrhea (absence of periods).
Essential Period Tracking Tips
Track Consistently
Record your period start date, duration, and any symptoms for at least 3 months to establish your personal pattern and improve prediction accuracy.
Know Your Normal
Everyone's cycle is unique. Understanding what's normal for you makes it easier to identify when something changes and may need attention.
Listen to Your Body
Pay attention to physical and emotional changes throughout your cycle. This awareness helps you plan activities and practice self-care when needed.
Remember: Your menstrual cycle is a vital sign of your overall health. Regular tracking with our calculator helps you understand your body's patterns, plan ahead, and identify any changes that might need medical attention. Whether you're managing fertility, planning activities, or simply staying informed about your health, knowledge of your cycle empowers you to make informed decisions and take charge of your reproductive wellness.