Menstrual cycle phasesThe 4 phases of your cycle, explained simply
Your cycle isn't a black box between two periods. Find out in seconds what phase you're in right now — no account, no app, right here.
Calculator
What cycle phase am I in?
Cycle length = from the first day of your period to the day before the next one starts. If you don't know it, 28 is the average.
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Overview
The 4 menstrual cycle phases at a glance
Day counts assume an average 28-day cycle. Yours can be shorter or longer — anything between 21 and 35 days is normal. One thing worth knowing: the luteal phase is fairly fixed at around 14 days. If your cycle is longer, it's mostly the follicular phase that stretches.
| Phase | Days | Hormones | Typical feeling |
|---|---|---|---|
| Menstruation | 1–5 | Estrogen + progesterone low | Fatigue, cramps, wanting to retreat |
| Follicular | 6–12 | Estrogen rising | Energy and motivation returning |
| Ovulation | 13–15 | Estrogen peak + LH surge | Energy high, peak fertility |
| Luteal | 16–28 | Progesterone dominates, then drops | PMS, cravings, water retention |
Menstruation
Days 1–5
Estrogen + progesterone low
Fatigue, cramps, wanting to retreat
Follicular
Days 6–12
Estrogen rising
Energy and motivation returning
Ovulation
Days 13–15
Estrogen peak + LH surge
Energy high, peak fertility
Luteal
Days 16–28
Progesterone dominates, then drops
PMS, cravings, water retention
Phase 1 · Days 1–5
Menstruation
Your cycle starts, by definition, on the first day of bleeding. Estrogen and progesterone hit their lowest point, the uterine lining sheds — and with it you lose 15–40 mgof iron, depending on how heavy your flow is. Feeling drained and craving quiet on these days isn't in your head; it's your hormone chart.
What helps: warmth (on your plate too), iron-rich foods paired with vitamin C, and ginger tea for cramps. For specifics, see What to Eat on Your Period.
Phase 2 · Days 6–12
Follicular phase
After your period, follicle-stimulating hormone (FSH) takes over: follicles mature in the ovaries and the strongest one wins. Estrogen climbs steadily — and with it energy, focus and often an appetite for new things. Many women experience these days as their most productive of the month.
Your body handles carbohydrates best right now (insulin sensitivity is high) and recovers fastest from training. For foods that match, see What to Eat in Your Follicular Phase.
Phase 3 · Days 13–15
Ovulation
The estrogen peak triggers the LH surge and the egg is released — the most fertile time of your cycle. Many women feel their most energetic and social. But ovulation is not a fixed calendar date: stress, sleep and illness can shift it by days. That's why every calculator (ours included) is an estimate, never contraception.
Nutrition-wise, antioxidants and fiber earn their keep now — fiber supports clearing estrogen afterwards. More in What to Eat During Ovulation.
“Ovulation ≈ cycle length minus 14. On a 32-day cycle it lands around day 18 — not day 14.”
Phase 4 · Days 16–28
Luteal phase
After ovulation, the corpus luteum produces progesterone. Your metabolic rate rises by roughly 100–300 kcal a day, insulin sensitivity drops, and when progesterone falls just before your period, serotonin falls with it — the biochemical explanation for PMS and cravings.
Magnesium-rich foods, steady blood sugar and permission to eat a little more make this phase far more manageable. Go deeper with What to Eat in Your Luteal Phase and How to Stop Sugar Cravings Before Your Period.
“Luteal-phase cravings are biochemistry, not weak willpower.”
Good to know
What if my cycle isn't 28 days?
The 28-day cycle is an average, not a requirement. Anything between 21 and 35 days is within the normal range, and mild month-to-month variation is too. Because the luteal phase stays fairly constant at around 14 days, the rule of thumb is: ovulation ≈ cycle length minus 14 — which is exactly how the calculator above does the math.
Consistently under 21 or over 35 days, sudden irregularity, or very heavy bleeding belong in a gynecologist's office — not in a blog post.
FAQ
Frequently asked questions
How do I work out my cycle length?
Count from the first day of your period (= cycle day 1) up to the day before your next period starts. That span is your cycle length. For a reliable number, track two or three cycles and take the average — apps like Bauchgefühl do this automatically.
What phase am I in after my period?
Right after your period ends you're in the follicular phase (roughly day 6–12 of a 28-day cycle). Estrogen is rising, a new follicle is maturing, and most women feel their energy coming back. Technically the follicular phase includes menstruation itself, but in everyday terms it's the stretch between your period and ovulation.
Day 3 of my period — what phase is that?
Day 3 is the menstrual phase. Your cycle starts by definition on the first day of bleeding, so days 1–5 (give or take) are menstruation. Estrogen and progesterone are at their lowest, which is why fatigue on these days is completely normal.
What phase am I in on day 21 of my cycle?
On a 28-day cycle, day 21 is squarely in the luteal phase. Progesterone dominates, your metabolic rate is up by roughly 100–300 kcal a day, and PMS symptoms or cravings may start appearing. If your cycle is longer than 28 days, day 21 could still be around ovulation — the luteal phase is the roughly 14 days before your next period.
How long does each cycle phase last?
On an average 28-day cycle: menstruation about days 1–5, follicular phase days 6–12, ovulation around days 13–15, luteal phase days 16–28. The key detail: the luteal phase is fairly fixed at around 14 days. If your cycle is longer or shorter, it's mostly the follicular phase that stretches or shrinks.
Can ovulation shift from cycle to cycle?
Yes, considerably. Stress, poor sleep, illness, travel and weight changes can move ovulation by several days. That's why any calculator — including ours — is an estimate, never a contraception method. For precision, track basal body temperature and cervical mucus.
Is a 25-day or 35-day cycle normal?
Anything between roughly 21 and 35 days counts as normal, and mild variation between cycles is normal too. See a gynecologist if your cycle is consistently shorter than 21 or longer than 35 days, suddenly becomes erratic, or your bleeding gets unusually heavy.
Should I eat differently in each phase?
Your nutritional needs genuinely shift across the cycle — metabolic rate rises by 100–300 kcal in the luteal phase, and you lose iron during menstruation. A balanced baseline diet comes first; syncing food to your phase is the fine-tuning on top. No dogma, no stress.
Never do the math again: the app detects your phase automatically
Bauchgefühl tracks your cycle and suggests recipes that match your phase. Start with the 2-minute quiz.
Get your recipe plan – freeOr keep reading in our complete guide to cycle syncing nutrition.
Disclaimer: This page is for general information only and does not replace medical advice. The calculator provides an estimate based on averages and is explicitly not a method of contraception or family planning.