Enter your last period date to find your current cycle phase — and learn what your body is doing in each stage.
Days 1–5
The uterine lining sheds. This is day 1 of your cycle.
Days 6–13
Eggs mature in the ovaries. Estrogen rises and energy builds.
~Day 14
A mature egg is released from the ovary. Peak fertility.
Days 15–28
Progesterone rises to support the uterine lining. PMS may appear.
To calculate your current menstrual phase, start by identifying day 1 — the first day of your last period. Count forward to today; that number is your current cycle day. Then use your typical cycle length (usually 21–35 days) and period length (3–7 days) to map where you fall: menstrual phase during bleeding, follicular phase after bleeding until roughly 14 days before your next period, ovulation around that 14-day mark, and luteal phase from ovulation until your next period begins. This calculator automates the counting and tells you your exact phase instantly.
Menstrual phase — 3–7 days
The time you are actively bleeding. Day 1 of your cycle.
Follicular phase — ~7–14 days
Begins on day 1 (overlapping with menstruation) and continues until ovulation. In a 28-day cycle, it ends around day 13.
Ovulation phase — ~1 day
The egg is released. The single most fertile day of your cycle.
Luteal phase — 12–14 days
From ovulation until the day before your next period. Relatively stable across different cycle lengths.
The follicular phase is the body's preparation phase. The pituitary gland releases follicle-stimulating hormone (FSH), signaling the ovaries to mature multiple eggs inside tiny sacs called follicles. One follicle typically becomes dominant. As the follicle grows, it produces estrogen, which thickens the uterine lining and boosts serotonin. Energy, mood, skin clarity, and libido all tend to improve during this phase. Many women feel most confident and sociable in the late follicular phase — it is an ideal time for new projects, intense workouts, social events, and challenging conversations.
After ovulation, the empty follicle transforms into the corpus luteum, a temporary endocrine structure that pumps out progesterone. This hormone maintains the thickened uterine lining and raises basal body temperature. If pregnancy does not occur, the corpus luteum breaks down, progesterone and estrogen plummet, and the lining sheds as your next period. The hormonal drop is responsible for most PMS symptoms: bloating, breast tenderness, mood swings, irritability, fatigue, food cravings, and mild cramping. Self-care in the luteal phase means prioritizing rest, gentle movement, warm foods, magnesium, and early bedtimes.
Cycle syncing means adjusting your exercise, nutrition, work, and social life to match your current hormonal phase. In the menstrual phase, rest and reflect. In the follicular phase, create and initiate. In ovulation, communicate and connect. In the luteal phase, complete and organize. Research on cycle syncing is still emerging, but many women report feeling more balanced and energized when they stop fighting their natural hormonal rhythms and start working with them. This calculator gives you the starting point: knowing exactly which phase you're in today.
There are four menstrual cycle phases: menstrual (your period), follicular (post-period to ovulation), ovulation (egg release), and luteal (after ovulation until your next period). You can find your current phase by counting the days since the first day of your last period.
Count days from the first day of your last period. Days 1 to your period length are the menstrual phase. From the end of bleeding until about 14 days before your next period is the follicular phase.
Ovulation usually happens about 14 days before your next period. The days after ovulation until the next period start are the luteal phase.
Find your average cycle length, next period, and fertile window.
Estimate ovulation, fertile window, and luteal phase timing.
Log periods, symptoms, and moods over time for pattern insights.
Track baby's growth week by week with trimester milestones.
This page is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a healthcare provider with questions about your menstrual cycle or reproductive health.